I get the impression that every attempt to make block lists ends up getting used to target people an admin of the block list doesn't like. I think the root of it is that the admins consuming the blocklist don't want to have to spend time on moderation and are remote from communities where the blocklist is happening. Also the scope of the blocklist is the instance. Compare that to community internal moderation (e.g. channel mods), where someone close to the community is invested in the health of the community and the scope of the block is the relevant community.

gestures broadly is going to be one of the common answers from anyone trying to ward off spam