The thing is, when the social justice left do things that are actively prejudiced against and intentionally hurt the minority groups they claim to be helping, you just don't hear about it because one of their core beliefs is that they're always helping by definition and they have enough power over the mainstream discussion that it's impossible to challenge.
For example, one of the last things the Labour party, who're the more left-wing of our two main parties, did when they had power here in the UK was write a special exemption in anti-discrimination law to deny trans women access to rape and domestic violence services at the request of a feminist lobbying group. (As in this was literally the stated purpose according to the official guidance accompanying the law when it was proposed.) Any discussion of how this happened or the lobbying group behind it was explicitly forbidden in the left-wing and feminist publications and communities with any reach. The press only turned on the Labour-linked lobbying group in late 2019, over a decade after the original law, when they started lobbying the Conservatives over the same anti-trans cause. The discussion of this has been so warped that the established social justice left view on the whole thing is that it shows transphobia is a right-wing thing and proves any attempt to equate the left with them (not just over transphobia, but any attempt to claim they're comparably bad in general) is a dangerous false equivalence.
For example, one of the last things the Labour party, who're the more left-wing of our two main parties, did when they had power here in the UK was write a special exemption in anti-discrimination law to deny trans women access to rape and domestic violence services at the request of a feminist lobbying group. (As in this was literally the stated purpose according to the official guidance accompanying the law when it was proposed.) Any discussion of how this happened or the lobbying group behind it was explicitly forbidden in the left-wing and feminist publications and communities with any reach. The press only turned on the Labour-linked lobbying group in late 2019, over a decade after the original law, when they started lobbying the Conservatives over the same anti-trans cause. The discussion of this has been so warped that the established social justice left view on the whole thing is that it shows transphobia is a right-wing thing and proves any attempt to equate the left with them (not just over transphobia, but any attempt to claim they're comparably bad in general) is a dangerous false equivalence.