I think without the possibility to earning money from posting, this forum would be at least a little bit better but also much less traffic, but maybe the traffic would be much better!?
Remove the signature campaigns and you will remove 90%+ of the forum traffic. Sure, overall post quality in that case would be better as people would only post when they actually have to add something meaningful, but at the same time forum would become completely irrelevant so in the end signature campaigns are necessary to keep this forum alive.
Bitcointalk allows you to make money while you are engaging in a genuine conversation.
Not really. You can be a mindless shitposter and still make a decent income thanks to the fact that there are more spots in signature campaigns than there are quality members.