All people have their own mental 'disorders' (or rather, 'specifics'), but INFJs are less aggressive in their kinds of oddness, which puts them in more vulnerable positions. Yes, I think the most powerful basis for type development is interaction with other people, and INFJs often have abusive family member(s) in some way (eg: ESTJ), which is not their fault, and doesn't make them inferior by any means. For all I know it seems such struggles help them to be wonderful people later in life.
I agree with this whole sentiment, especially the parts in bold.
My whole life I've been the victim of people treating me badly because I am 'odd'. More often than not, these are ESTJs who have insisted, with a great deal of demanding, that something was very wrong with me that needed to be fixed. I've lost a lot of jobs because of some hateful ESTJ bosses who just couldn't accept my manner or my methods, despite having superior results. For example, I was once fired for not pushing hard enough when I was the
top salesperson in the
region, not store, not district, not state - region. My boss was convinced that I was doing it wrong. No, really. He insisted that I switch to high pressure sales and 'the formula', because my low pressure sales and being genuine with people weren't effective enough. And then a year later, I had the exact same thing happen again. Top salesperson in the region. Not effective because I didn't do things the 'standard' way. ESTJs. Ugh.
I don't know if these experiences cause us to be wonderful people though. I've always felt that I've had to fight to stay the way I am in a world filled with frustrations and obstacles designed to try to beat it out of me. It's as if life is constantly trying to force me to 'turn to the dark side' and make me become hateful, bitter, and selfish ...but for some reason, I just can't... even in the face of them. It's just not my nature, and if I can get away from these sources for even a moment, I come right back to myself very quickly as if those things never happened. I think it is just our nature.
If anything, I think INFJ emotional problems stem from the abuse we have to deal with for being 'odd'. To put this in practical tangible terms... If someone had a disability that you could point to, like being in a wheelchair or carrying a blind person's cane, or even had a mental disorder that prevented them from working, people make accommodations. But if you have a personality that certain people just can't accept, and therefore won't let you work, even when you're great at your job, it's worse than having a legitimate disability because the person with the disability requires fair treatment under the law, as well as on an everyday moral level. They get pitied, sometimes treated poorly, but when it all boils down, people accept and support them and their condition. When you're just a little odd, there is no pity or sympathy, and there sure isn't any provision. You're just out on the street. Next.
Having to deal with things like this, whether in careers, relationships, friendships, or any other kind of social situation is in my opinion what causes us to have our emotional issues. If a parent constantly told their child that they would never amount to anything if they don't change from being retarded or having paulsy, people would be outraged. (And I'm not saying that doesn't happen) But, when a parent does the same to their kid for being 'odd', somehow it's acceptable to society. Somehow it's okay because people assume that we can change who we are. The problem is, our cognitive function preferences are as inherent as Down's Syndrome or any other condition. I know I'm making a mountain out of a mole hill, but the cumulative effects are what cause us a lot of problems over time.