They'll then defederate also from you. The argument goes, you're a nazi/facist/racist/*phobe, because you associate with (== did not defederate from) the designated nazi/facist/racist/*phobe.
Yes, it's that toxic. Go subscribe #FediBlock hashtag if you don't believe me.
Ok, so what? Let those people block you then, sounds like people you probably don't want to interact with anyways?
I've seen that, and I'm not sure what's supposed to be toxic. It's community-organized filtering of unwanted views, for the people who want to engage in that. I don't agree with that, so I don't participate or do that myself, and I also don't seem to face any negative consequences because I'm not participating in that. What am I supposed to be sad about here, that some people don't want to listen to my views?
Witch hunts and guilt by association are generally seen as toxic. If you disagree with that I'm not really sure what to say as it's a rather fundamental principle from my perspective.
> sounds like people you probably don't want to interact with anyways?
That's all well and good when it's a single user instance or small group of friends. But often enough it will be a much larger one with unknowing participants caught up in it. Blaming them for choosing the "wrong" instance is about as productive as blaming people for using facebook - technically correct but that's about it.
That said, the AP model seems like the least worst to me. Every option I'm aware of has significant downsides.
>Ok, so what? Let those people block you then, sounds like people you probably don't want to interact with anyways?
The problem is when this is a large server with people you know using it. They suddenly disappear from your feed. And those people may not have even agreed with the reason for defederation.
At that point, the only way to connect with your friend(s) is for you or them to find new servers that haven't (yet) gotten into a defederation slap fight.
The TL;DR of the problem with Mastodon is that you basically need to pin your identity to what is essentially a small internet community/forum and then give them full power to decide who/what you can consume while your identity is tagged to their community.
Look, life is complicated and not a single issue, contrary to what admins of many of those fedi instances would like. Typical human has views on multiple subjects, but it takes only a single incorrect opinion expressed to have you ejected. Worse yet, it happens by leveraging the admin of your instance: they go to the admin and tell him/her that if you're not banned, they'll defederate the whole instance. IOW they're bullies, and bullies squared at that: they designed a whole protocol to enable bullying.
Again, go check #FediBlock. If you'd like a specific example of the single issue vs multiple issues, pay specific attention to trans vs black conflict there and see how it is played by both sides.