Centrists are at least trying to be reasonable.

Not in my experience. They don't want to appear to be what they are, assholes. Therefore they will nod and agree with progressive policies but when push comes to shove then they unleash the usual bullshit, "now is not the time", "you're asking for too much", "how can we afford it?", "baby steps", and so on.

Take universal health care. I'd rather not have my time wasted by a conservative simply saying, "lol, hell no, you commie" than deal with the bullshit hand wringing of a centrist where they expend so much energy trying to convince themselves they're not the bad guys.