So you are saying that people in third worlds don't have a right to benefit from Bitcoin? I remember reading some stories about how some guys that were unfortunate to be born in some of these shitholes were making more money thought signature campaigns than they did working a real job (where they are exploited for peanuts). Isn't this beautiful? Bitcoin is liberating people, this should be celebrated in any case.
Anyway, I live in a first world country, and unemployment is only getting worse. Getting some extra bucks a week is greatly appreciated. Removing sig campaigns would be removing an actual use case of Bitcoin that directly benefits real people (both the people getting paid and the people improving traffic into their websites by promoting it through them, not to mention the website itself benefits as traffic is way higher and it ranks better).
I would also stop buying stuff with Bitcoin because I only buy stuff If I get paid with it, buying Bitcoin then buying something with it makes no sense.
If you want to be elitist, maybe you could disable signatures in a specific new subforum called "technical talk" or something, where it's impossible to get paid if you post there, filtering any possible spam. Other than that, doing this with the entire forum is a mistake.
If someone spams, mods see it and ban them already, so this is really a non issue. If the colorful banners offend your eyes, it's also a non issue since disabling ads will be possible soon for Hero+. I personally tried a script when I wasn't in a sig campaign to disable all signatures and the forum looked extremely sameish. My eyes have become used at posts being separated by banners at this point.