I think a perfectly acceptable line to draw is "Is it reasonable to expect a large majority of the people on this instance would want this other instance blocked?" If the answer is yes, block them. If somebody has a problem with that, move to a different instance.

I don't really understand what the problem is.

My issue with other instances is largely their users and the new instance block feature merely blocks communities, not users. I’m very fine with continuing to avoid users of loli/pedo/alt right condoning instances.

AFAIK you can block the POSTS of another instance from your feed. And only posts from communities hosted on those instances. But their users' comments and posts will still appear for you everywhere else.

Do instances want to remain legally protected by blocking all those instances?

Er, what laws are we talking about here? You do realize that instances are run out of many different countries with wildly differing laws on speech, right? Also that very, very few countries (probably zero) are going to have laws on the books about fediverse instances federating with one another?

Honestly, I'm fine with the owners of various instances making decisions to federate or not federate with others. That sort of decentralized control is one of the benefits of federation. There is no single point of failure for the whole ecosystem. If one instance's admin goes off the rails, it's easy for people to know about and shift to a different instance. Sure, it also means that an admin can go off the rails and start defederating anything and everything they don't like. Again, that's not a problem with lots of well known instances out there for us to choose from. And it means that those folks with niche interests can build their own safe spaces to discuss their interests, without every third post being "haha, yur dum!".

If you really don't like the way your current instance is being run, then spin up your own and follow your own rules. Maybe you're right and that's what everyone really wants. And maybe not, and you'll quickly find yourself a community of one. But, let's drop the talk of "legally protected" when this sort of thing has nothing to do with the laws of any country.

In the decentralized network of the fediverse where freedom of association is king, you're free to start your own instance that will federate with everybody. Of course, the other admins are as free as you are and may decide to not federate with you. Such is that degree of freedom.

What do yall think about that?

Instances can (and should) block whatever other instances they want, based on whatever reason they can come up with. If your instance blocks an instance you want to use, either switch to another instance or host your own.

yeah, though lemmy.ml afaik (haven't manually checked recently) only blocks porn, spam or really messed up instances, which is fine with me.