Especially in the US, where both parties are globally “right” in both political and financial aspects, a lot of time claiming to be a centrist means that you like capitalism and bombing other countries but you support LGBT causes and are pro-choice. I think, online and especially on lemmy, that the vocal left-wing voices (correctly) see this still as aiding the right but being too cowardly to admit it.
This also ties back to the MLK quote about the ‘white centrist’ being the biggest obstacle to his movement, because they may say the right things and appear to be helpful but take no action for the movement. By staying centrist and trying to meet in the middle, would lend credibility to the voices on the other side.
Thank you! I should’ve linked to it. The actual text does a much better job of answering OP than my attempt to summarize it.