I think disappointment in people is a very reasonable attitude. In fact I think cynicism towards people in general is one of the core defining attitudes of our time, and it transcends political boundaries.

But as a filthy leftoid, I believe that there are socio-economic forces which are responsible for how people are in a given era. The spread of misinformation on the internet, social alienation, poor education with no media literacy, logic or critical thinking - these are not innate flaws in human kind, they are failures of society that can be fixed.

So you can see we have a real problem, because leftism and even liberalism is built upon respect for and faith in humanity - but very few act like it.