Well, there's a self-proclaimed Left which, though probably having started out with good intentions, is all about "lets classify people on visible things they were born with and then presume things about them purelly on their "classification" and treat them differently".
If this sounds strangelly like the far-right thinking that's because it is kinda derivative: the same architecture of deeming individuals as worthy/unworthy likely-good/likely-bad because they were born with certain characteristics is in used, and then they just swapped the categories and called that "being progressive".
Then there is the tankie Left, which also started with good intentions but seem to have confuse the recipe-book of slogans and the Party über alles discipline invented in the late 19th century and early 20th century by middle class intellectuals to inspired the near-illiterate masses of the time to create an utopian leftwing world (which didn't work) with the actual thinking Principles and Intentions from which the rules were made. Because there people follow the recipes rather than actual principles, you went up with ridiculous ideas directly opposed to "the greatest good for the greatest number" principle like supporting Putin's invasion.
The followers of such "Lefts" hate it when their faith-like beliefs are examined against the actual Principles of Equality and "the greatest good for the greatest numbers" and found often to be directly opposing them, just like when you grab some religious book or other and point out the inconsistencies in it: there is no greater hate than that of the faithfull who sees the basis of their Identity be examined under the cruel light of logic and found to be mainly bollocks.
Or in other words, I think the Left here is a lot more the product of thinking things through and concluding that it would be a lot better to live in a World with less poverty, more equality and were a few did not amass more power than whole countries thanks to their wealth, and continuing to actually continue to think things through when face with slogans from the tribalist flag waving slogan parroting and social-circle-jerk groups which call themselves "Left" and which are the leftovers from Marxism in the XXI Century and the Neoliberal-inspired "in the greed is good context, lets pursue personal-upside maximization as an 'Identity' group instead of individually so that we can claim we're lefties".
PS: If it sounds I'm raging against the Left here, that just because I find the pettyness and self-serving sociopathy of the modern Right to be self-evident. I actually don't think you can be a true leftwinger genuinelly fighting for the greater good if you just blindly follow slogans and tribes.