Do you think people deserve love- is it a right? How would you personally quantify a person's lovability?
Do you think all people are lovable? Do you think that "good" behavior deserves a relationship? How do you define your own relationships? Have you been in relationships where the other person used this argument? What do you think the relationship is between expectations and the quality of a relationship?
Wow, so I wrote out a nice long response, then accidentally deleted it. I will try to recreate it :/
Ok, so before I begin, I think a distinction must be made about the type of love. It seems to me there are several kinds of love, for example: love of a spouse/significant other, love of a family member, love of a friend, love of a pet, love of an object, self love, superficial love, etc (however an argument could be made that some of those aren't true love). There are also distinctions on the way a person can be loved. This part seems very similar to the discussion I commented on "what is caring". I will post a link to that after this. I will assume you are talking about the kind of love of a spouse or significant other. I will call this marital love.
To the question of do people deserve love/is it a right, I would have to say no. People do not have a right to be loved. I think love, like trust, is earned. You do not just walk up to some person you have never met and fully and completely love them on the spot. To step away a second, I would say that caring and loving are very similar, in fact I would go so far as to say they are the same thing. However, I think our vernacular tends to say that caring is a lesser form of love. You might care about a person, but that does not mean that you would love them. Now back to my point. For two people to actually love each other, it is a process and it is not easy. True love cannot be taken or given, and I do not think anyone has a right to be loved. Each person must earn it by being who they are. If two different people are who they are, and they are similar in personality to the point that they mesh well together, then a connection is formed. What is done with that connection is determined by the two people, meaning if they wish to be friends or significant others. So basically love is earned when two people who mesh well enough together choose to accept and go through with loving each other.
That being said, I also agree that people should/need to be loved. Humans are after all a social creature. It's just we all go about being sociable in different ways (yes there are a few exceptions, but that is a very small minority). I think this desire and need to be cared for is a natural inborn thing to humans. Personally, I think it is very obvious why each of us would desire to be loved. To be loved by another person is a magical and unique thing. Something that should be treasured once achieved, however it should not be expected.
To your next question, I would say no, love is not quantifiable. Any one person could be loved in many different ways, and different people can love different things. For example, my mom loves guacamole. Me, not so much

. Or, both me and my friend love dogs, but I love dogs because they are loyal, and he loves dogs because they are fun. Because a thing can be loved in different ways and for different reasons, there does not seem to be a quantifiable way that can be set to say this person is so so & lovable that is constant for everyone. Here's an illustration. Take persons A, B, and b. Persons A and B could not mesh well, and therefore not love each other, while persons B and b could mesh well and love each other. So to person b, other person B could be very lovable even though to person A, person B is not lovable. There does not seem to be any constant, so it does not seem quantifiable.
As for if all people are lovable, I would have to say I don't know. If you consider statistical probability, then it would seem for any one person, it is very likely that there is some other person on the planet with whom they would be compatible and would be loved by. But that leaves questions of will they ever meet, will any proper consideration be given to loving each other. It is also just as likely that there is some people out there who literally do not mesh with anyone and therefore are not lovable. However there is no way to test or prove this either way. Too many variables, so I have no idea. I would like to believe that there is someone out there for everybody though.
Is good behavior deserving of a relationship? I would say no based on the same point made about do people deserve love. I think being good is the best way to get a good relationship. Not that it is deserving of a relationship. Also, just being good to mean polite and kind is not necessarily enough. Consideration must be given. Any good relationship (like what skarekrow was talking about) is a two way street of give and takes where both sides must mesh well and be happy. It doesn't matter how nice you are, if you don't mesh well, then you won't have a relationship. However, like I said, being good I think is the best way to get a good relationship. No one should expect to be loved. However it is really really nice whenever it does happen. Real love is a rare thing. Don't force it. When it finds you, you will know, and you are lucky for it. If it is meant to be, then it probably will be. If not, let it go. However this is not to say just sit passively. A good relationship does require effort. Active participation from both parties.
I'm not sure how to define my own relationships, and I'm not sure if it would help. The closest relationship I have is my best friend. We both understand each other and can talk about anything. However that is what I want in relationships. Honesty and openness. Acceptance and understanding. I would expect the same (and then a little more) from a significant other. Different people might not like that or put as much emphasis on it. We cannot tell you how or when to love. Everyone is different. It depends on if you mesh well with the other person or not. If you don't mesh, then its not meant to be. However, I will say it again, a relationship takes effort. Not everyone will be exactly the same or completely understand. It more depends on if you get along well together. And this even doesn't mean no fighting, because fighting is sometimes needed. To say what is a good relationship is very complicated. I'm not going to get into that unless asked, because that is a very long discussion.
I have not been in another relationship where the other person used that argument. The relationships I've been in with a significant other (never became very significant) we bother understood the idea of if we were right for each other or not. Neither of us expected the other to love them. We just saw that we weren't right for long term relationships, and subsequently moved on.
I think I might have said do not expect another to love you, but this is not to mean there are no expectations in a relationship. You will have your own expectations of the other person. For example, I expect my friend to listen if I'm in trouble (and vice versa). If he ever I were in serious trouble, and he wouldn't listen, that would be very harmful to our relationship. The same is true in couples. You will have a core set of values unique to what you want/desire. If that person fulfills them, then they mesh with you. You should also know the other person will have there own unique set of core values. If you fills those you mesh with them. However its not this cut and dry. Remember that give and take thing I mentioned? this is where it comes in. Sometimes you might have to give on some of your expectations and sometimes the other person might as well. However do not give to much. For example, I never swear. I would expect the same from my significant other. However, if they swear occasionally accidentally, I will accept that. That is me giving a little from my expectations. However, if I had a girl who was hussying around with a bunch of other guys, I would be saying no, its over. I'm not gonna give much on that topic. As for the quality of the relationship, I would say it depends on how well the two people mesh. If the two people don't have to give much to make the relationship work, then it is a high quality. If they have to make a lot of gives to make the relationship work, then its not very high quality. But this also depends on how happy the person is. If they are extremely happy, then it would also be a good quality, but if they are miserable, then obviously its not a good relationship.
Hopefully this was helpful. I hope this made sense, I made a lot better sense the first time I typed it out :/. oh well. If I need to clarify some points or you have other questions or disagreements, feel free to point them out.