Beehaw mods had issues moderating a flood of new users and low quality posts from here. As they put it, it was more “we don’t have the tools and staff to handle tons of new people” and less “we don’t like SIJW”.
To add to what others have said, the reason beehaw defederated is because they have particular rules (eg no downvotes) that they're very strict about to ensure that their instance is the safe space they want it to be. It's not so much that lemmy.world and sh.itjust.works users were acting up against beehaw, just that beehaw expects users to be very well behaved in their instance.
You can't say "we" on a fediverse system, because the post is gonna be seen by everyone everywhere. I'm not on sh.itjust.works, I'm viewing your post on kbin, and it's also gonna be seen on all the other lemmy servers that are federated with yours.
The short version is because the mods there are very special (in abad way) and like to gatekeep their echochamber as much as possible.
The long one is because they have a vision where their platform is more safe to its users which should be more likeminded individuals and would like to keep it as true and safe as possible acording to their vision, which im not sure what it really is, from what i heard is that they are very left leaning but in an extreme way and dont like discidents, so anyone thats not as likeminded as them is just straight up not welcome then. They probably call disicidents harasers and just ban them. So an echochamber.
Now officially what they said is that everybody but them sucks at moderating and wont refederate untill they dont suck anymore. They say thats because everyone doesnt have sophisticated tools for moderating but i think they just whant everyone to enforce their ideals everywhere else, and if thats the case i believe we are better of without them.
So I recently had a lengthy conversation with the admins over at Beehaw about this. And the impression I got was that it really came down to two or three major outstanding issues.
number was was moderation tools. We must get to building better moderation tools.
For number two i'll just attach a screenshot. You can click to view it because I don't want to clutter up this thread to much.