Principles have cost me a great deal over my life, but I still have them. I most likely will always have them. There are things I will never compromise.
I respect those that choose principles based on truth and what is fair, among many other possible things, mainly because I understand those people's choices as they were my very own through experience. In other words, I understand why they stand for what they believe in. I may not always agree with what they might stand up for, but at least they stand for something. It is much easier for one to sit on the couch and choose nothing. Taking the easy way out may not always be the best possible choice, if you know what I mean.
It is difficult for me to respect someone that has no principles when it shows to reflect darkness rather than light; selfishness before honor or dignity.
Those that have little to no principles are fine with me as long as they choose the right path when time knocks at the door to do so.
I would rather enjoy discussion with someone whose principles differed from mine, but only concerning subjects I wish to spend the energy on. If it were that important to the other person, I would still spend the energy for their sake. I think those that are selfish or have an "I" mentality are the ones I have the most problems with when trying to see things their way, even though they have a right to be so. Maybe I just do not hold them in high esteem.