I haven't checked all 1xbit participants and quality of their posts, but I'm not against your suggestion. It's true that you probably wont find high quality posters in 1xbit campaign, but maybe not everyone is bad enough to get signature ban. IMO, this question should be solved case by case and not simply disabling signatures for all participants.
For me 1xbit content doesn't look as bad as Yobit/Cryptotalk campaign. Or maybe I got wrong impression because number of participants is significantly smaller and their content isn't that visible.

Gaystar. Seriously? I thought that only 12 year old kids are doing such things. When you have lack of arguments, ad hominen begins...