This is very close to the Nazi point of "just asking questions" or when they say it's just free speech. Not saying you're arguing it, but it is a very thin line.

What's the line then? Why do people ban Nazis and not tankies? Tankies are authoritarian, they defend the massacre of Ukrainians, the Uyghur genocide, and other historic "socialist" atrocities. Why do we give them leeway? Are they skirting the line just enough? Are they intentionally using the optics of socialism to do so? Etc.

Keep in mind, just because someone blocks someone or an instance it doesn't necessarily make the space an echo chamber. We don't know if they live in a state or work in a place that is blasting Fox News 24/7. They may be very active on Twitter exposed to that sewage. Heck, the liberal point of view is quite a lot as is with the way they are defending Israel.