You can milk the shit of this forum with 100 alts. I am sure you are smart enough to figure how.
Not really. You can't maintain 100 alts with decent quality to earn from 100 signature campaigns. There was one guy doing it for a very long time with 3 alts (and maybe more that we don't know about), but there's no way someone can maintain much more than that
and keep his post quality high enough to earn more than just bounty spamming.
Where did I say that he has to actively use all 100 accounts?
With that many accounts he can join scan signature camps like 1xbit without any fears, join lotteries, giveaways, and if he is a teenager with lots of free time yes he can manage and post with multiple accounts. Not done, he can use his army of alts to support his narratives and create a presudo forum rockstar.
I think It is possible. Only thing he needs is, time and determination and yes, it would pay, a lot.