I tend to give people the benefit of the doubt, and treat the assholes as outliers. It's too easy to assume the worst, but that's what a lot of people do these days. It's kind of sad.
I'll agree that saying "better safe than sorry" is probably the wrong way to view life, but taking what other people say with a grain of salt lets you question what people say more and come to your own decisions about life.
Also, "people suck" includes yourself, so you can think about it as a way to think about what you are saying and doing and see if it is up to a level of quality that you are comfortable with.
Even better though, is when you meet truly kind people, it is a surprise and pleasure to work with them.