You must realize that there are probably an abundance of bitcointalk members who are already starving and the income from these bounties perhaps provides them with just enough money to eat.  There are some very poor countries where $1 USD stretches 10 times or more than it does in its origin country, the United States.  And if you are perplexed that such members resort to creating multiple accounts for the purpose of enrolling in as many bounties as they can manage, you shouldn't be. 

The work opportunities that ICOs provide are harmful sometimes, to be sure.  But let's face it, if you're unemployed with no skills and a hungry family to feed, doing signature campaigns and translations and social media promotions has to be a godsend, and one would be either insane or too pride filled to refuse to do them. 

I doubt most bounty hunters expect to become wealthy from their earnings.  More likely is that they convert the tokens they earn to bitcoin, which they can either spend or convert to fiat.  These are not true believers in bitcoin.  It is just a means to an end for most of them.

Some of them, I am sure.  Attaining a high rank here is much more difficult nowadays because of the merit system.  That's a stumbling block for the vast majority of them.