There is no way to disable sigs for individual users.
I'm sure that quite a few will be upset with the inforcement of the rules, but 99.44% of them are not here to comtribute to the community anyway.
I think everyone has to ask themselves if you're here to contribute & learn from the board or are you here to get their sig files shown as much as possible.
If it's the latter, you might want to find a new home:
http://www.allofem.com/boards.php