I too have phat bloated sig pictures on the game forums I frequent, no matter what codebase the forums use or what features they offer. Compare this to the ascii sigs on newsgroups or perlish signatures here. Signatures seem to be more influenced by what the community as a whole adheres to rather than the ease of access to an IMG tag. Sure it might make perlmonks easier to troll, but most trolls would take the time to learn your forum software anyway, so I think that point is moot.
I think you under estimate the usefulness of other tags such as strike through when editing ones own post, so although I agree with a minimalist approach I might like more formatting options than you. All in all the powers to be could choose which formatting options to make available as buttons (such as only having bold, italics, paragraph and code tag buttons).
I also think you misread my desire for said buttons, I don't care for them or need them, but others might prefer them
Confucius says kill mosquito unless cannon