Burn out sometimes comes because we're in a bad place--working in a toxic environment. But more often it comes because, as you said, we make it a negative place. I think it is very easy to fall into the trap of getting angry and frustrated by the shortcomings of other people. It is unlikely you can have much impact on them but you can stop feeling abused by them if you just focus on your own work and your own attitudes.

My best colleagues and I have instituted a rule. Short time limits for complaining. Work related topics are not allowed at social gatherings, which includes lunch! And if a subject does need to be addressed, we set a specific meeting time to deal with it so it doesn't take over other interactions and make a whole conversation negative.