Why can't you just block the instances you don't like on your preferred client? That's what I do, and I don't see comments from any user account on any instance I block. I think defederation should be reserved only for the most absolute eggregious problem instances. Instances the CP spammers were from, if you were around for that in the early days here, for example.

As long as they aren't spamming CP and brigading to vandalize posts and stuff, I don't think any instance should be defederated, even if I dont agree with the users there.

Like, I find Blahaj instance users generally annoying. I have never had a positive interaction I can remember with a Blahaj instance user. I can remember quite a few negative ones though. But I don't think Blahaj should be defederated. I just blocked the instance on my client and now I don't see any of their posts or comments (except via modlog, mod view, etc), they can still access communities here, and users here can still access communities there. Wins all around. My personal opinion shouldn't be a reason to remove everyone elses access to an instance they might like.