I didn't know it was the most active but your question is a little bit provocative. Of course it wouldn't be the same at all, I'm dreaming of a Tiwer Ivory of Gambling where signatures wouldn't be displayed to let real gamblers having interesting discussions without this huge amount of spam of non-gamblers.
Participants of a gambling signature campaign are also curious about that site so most probably, they can be a potential gambler as well and this is why some gambling signature pays their hunter through their site to encourage them to try the site and have some bets. Signature campaign has a big impact in crypto gambling today, and not just in gambling but also in other projects. This forum has been very effective in producing good projects, I've seen a lot of good projects already.
They don't need to post in the gambling section to visit the casino they are advertising, so if signatures were not displayed in the gambling section it won't change anything about that. I think it would be even more profitable for casinos, because people wouldn't realize so easily that the user promoting the casino in his signature and avatar they see doesn't know anything about gambling and casinos and don't care about the specific one he is promoting.