I hate aibu as well, I always have.
What annoys me about the posting of serious and sensitive stuff there is the fact that the context is flippant and aggressive and rather childish, and these issues don't appear to sit comfortably within that context, not to me anyway.
Seeing a thread title in A/C such as 'AIBU to think my husband shouldn't hit my head against the wall for forgetting to clean his shirt' just makes me feel a bit sick. It seems to imply that either the OP doesn't take the issue entirely seriously, or they don't expect their audience to.
It's one word: inappropriate. Though of course all sympathy to the OP in a situation like that, wherever they decide to post about it. That's not the point.
Most threads in AIBU annoy me though so maybe that's something to do with it. I hate the whole thing.