This is still a much better suggestion compared to removing signatures for all of the users. There are some quality signature campaigns and hard working campaign managers still on site, so it's better to regulate it instead of banning it...
I usually don't belive that those jr. members and newbies posting in the alt section are not bots, simply, they post rubbish, I just can't belive they are humans and do this manually day by day...
So if they are bots (or people who don't speak English) and they leave, the forum won't lose anything but only traffic (which is still important, if we want to be the first and most active bitcoin related forum, prior to reddit, etc...)
I just feel sorry for the very few newbies, who come here to learn about bitcoin (really) because they will suffer because of the shitposter army... if we implement some strict regulation for the newbies, jr. members, etc...
If anyone had found a simple solution for this problem, it would have been implemented already, so there's no simple solution at all. If there will be a solution, that will hurt, the question is whom and how much...
You just can't report all of the spammers and get them banned, because if you get one banned, two or three new shitposter will register immediately... (unfortunately, even if you won't get one banned, the new shitposters would still register...)