Bad Decision?

Everybody at work is complaining about how shit their job is or they're quitting and leaving for better jobs. Its very unsettling that 3 people have left the company in the past 3 months. I'm wondering...maybe I picked the wrong company. I also wonder if its human nature for people to bitch about their jobs or if there is a company (or many companies) where people actually like doing their work. In the end it is really up to me whether I like a job/company but the attitude of my co-workers does impact my decision to a certain degree. If I leave here for what seems to be a better environment will I face disappointment and the same attitude at a new company? Do unhappy people fill the confines of every office space?