I think this was more of a feature of 10 years ago - that being, people meaning well and learning about political theories for the very first time, but then ignoring all nuance and using those concepts to bully each other instead of actually make the world better. Vox has an interesting article about that phenomenon as it played out in fandom circles, and if I remember right it does talk specifically about Tumblr. Huge difference between actually working toward social justice, and simply recycling justicey-sounding words into arguments and harassment campaigns. Things do seem to have leveled out a lot as people have aged and norms have shifted a bit, but I can understand someone feeling wary of the site for that reason.