Federating with certain instances increases their moderators workload. Their moderators/admins are expected to perform at a high level (provide a safe place).
Beehaw respects their moderators/admins. So without the adequate moderation tools, defederation is pretty much their only option.
They are considering other community platforms. They are hoping federation/Lemmy works for them, but they aren't willing to compromise on their community goals

[–] Blaze@feddit.org 2 points 2 weeks ago* (last edited 2 weeks ago)

I am aware they want to switch to another software, and that's fine.

It just seems a bit ironic that they complained a lot in the past (and rightfully so) about the lack of moderation tools, but now they don't offer their users a very powerful one: user-level instance blocking.