Shitty gambling adverts from people's signatures. You do nothing to promote a positive all inclusive image of Bitcoin by pandering and trying to profit from others vices/addictions.
Just because someone is a part of a signature campaign doesn't mean that they are only posting to promote said signature!
Personally, I am more turned off by people who put their Bitcoin and Litecoin addresses in their signature hoping for a handout

It was fairly novel back in the day to be able to tip people who posted stuff that was helpful. There hadn't been a way to do that before. We take it for granted now, but, being set up to receive tips was kind of a way of identifying ones self as someone who was trying to be helpful...