I think maybe you had just one non-friend - the one that told you that caustic lie. Just a thought.
Seriously, the world isn't all fluffy fuzzy happiness. Sometimes people honestly dislike and even despise one another, but they can still produce good work together. Gilbert & Sullivan are a good example.
Edited to expand: I already sandbox my personal and work lives thoroughly, so it's not going to cost me anything of significance beyond the job if I lose the job - not that that's not significant, but it's not my whole life, either. If, to a good first approximation, everyone where I work hates me, then I'm already going to lose the job, because with that many people looking to put a knife in my back, someone is going to succeed.
The odds that knowing this is true will make it possible for me to change it are effectively negligible; on the one hand, if everyone where I work hates me because of my own behavior, I'm not equipped to change anyone's mind, and on the other, if everyone where I work hates me because of something that isn't actually under my control, everyone where I work still hates me and I'm literally the last person in the world who's going to be able to do anything about that. Either way, I'm screwed in a way that foreknowledge isn't going to do anything to help; the best that'll happen if I find out ahead of time is nothing, and the worst is that I'll make my situation even worse. So where's the benefit in being told?
Either OP changes his behaviour to better-please his colleagues, thereby improving their work dynamic, or he cuts them, thereby improving his circumstances. Without accurate information, he's unable to make an informed decision.
I personally believe truth to be more important than happiness, and I would want to know the truth even if it made me unhappy. Other people might prefer happiness to truth, which is fine, but that's not what I would choose for myself.
I tend to take the former approach, but experience has taught the latter works better. Inflicting pain on a friend, even with their best interest at heart, is a good way to lose friends.
That really doesn't follow. I've had to maintain a pleasant working relationship with folks I've cordially loathed (and I'm certain the feeling was mutual). In every situation, we were friendly, pleasant and worked together well — but at the end of the day, we couldn't stand one another. Sometimes you don't get to choose your colleagues: your only choice is to quit or to continue.
This use of the adjective originates in the philosophical concept of "ontological parsimony", which is basically Occam's Razor with lots of the sort of added complexity you generally find in epistemological analysis.