The truth is that it become a race to the bottom with a lot of open source projects, specially the ones that are not hard to replicate.

If the author made the project GPL, someone else would create a similar library with a more permissive license, which would end up taking the market and making the original library irrelevant.

GPL for students and open source projects, paid license for orgs and companies. GPL itself isn't really a way to get paid for your work.

I was speaking more to preventing companies from using your open source work, but I guess in this instance the emphasis is on getting paid.