So for the first part, I don't disagree at all. I just don't think the logistics or theoretical necessity is a bearing on the symbolic-ness of it. Same for the effectiveness of it. Even if it changed literally nothing and no one would ever know I still wouldn't shake hands with someone I considered evil.

I don't see defining a subset of what you consider evil, like dissemination of hate speech, to be a downside.

There's a lot of complex questions around a platform curating ideological content which could possibly make them loose certain platform protections. Right now most platforms are roughly content neutral because it allows them to be viewed as platforms, rather than publishers. This is more a response to the claim that there's no reason for them not to remove ice. It may or may not be compelling, but it's a real reason.

As for the use of the word "service", sometimes my hands type slower than my brain thinks. My intent was to convey "those who develop and control the mastodon license". Hopefully my original statement makes more sense in that context.
Those are the people providing the printing press schematic analog. Obviously an idea can't support an ideology in that sense.

I'm not of the opinion either supports them in a way that's worth getting angry over.
We also aren't talking about being angry at ISPs for being willing to deliver packets to and from ice or Nazis, or any of the other entities that do less then the most they could possibly do to distance themselves.