The reason people argue against so-called “moderate” views here is because they represent the obstructionist wing of the Democratic Party: owned by corporations, giving lip service to their constituents, and blocking every progressive attempt to implement wildly popular programs like Medicare For All and aggressive climate change measures. Many independents and nonaffiliated voters are (like Bernie and most Americans) to the left of moderate politics.

But I see "centrist hate" against unicorn boogeymen more than anything. /r/enlightenedcentrism is a satire sub that doesn't even have real content most of the time, it's memes about people who seem to exist as a tiny fraction of a minority.

The people you're describing, representing the obstructionist wing of the democratic party, owned by corporations, etc., is the exact opposite of what I usually see being called "centrist". Comments that call out corporate money on the democratic side get called centrists!