It's not hard to know what they're for. They do not need an explanation that YABU means the opposite of what your YANBU is. We are not toddlers.
I refuse to even answer the AIBU threads now if the op explains what you're voting for. I wanted to partake in the Friends one, but straight away, silly explaining what you're voting for, it's not necessary.
Perhaps if people stopped using AIBU for such inane questions like AIBU to ask you if I should eat cheese, then it wouldn't be as big of an issue.
You're ruining AIBU for me, please stop.