I think for a lot of libs it's this willingness to say 'No, things shouldn't be like this" that makes them so angry when people push them from the left. They take it as a mark of their sophistication and maturity that they have constructed an elaborate series of excuses that mean no one should be mad, liberalism is the best things can realistically be. Given that a lot of criticism from the left comes from people who clearly know and care a lot about how things actually are and make an effort to understand what's happening, they can't just handwave you away like they do to CHUDs, and they're not prepared to defend the premise that things HAVE to be this way, they've just assumed that.