Saying things like "No amount of money is going to impart good taste and best practices onto these projects" is insulting the people who wrote it with no real basis. It's not helpful and it makes you (and some other people in the thread) sound like a jerk.
[0] https://www.dimastr.com/redemption/home.htm
If that's true, do you think that having money might possibly be helpful to that effort?
Use the standard java logger and move on, it's that easy.
If you don't want to work on it anymore that's OK too. Open source libraries are generally not held to particularly stringent requirements by the vast majority of people - perhaps accepting an obvious patch in a critical situation, at most.
You obviously can pay people. They're called employees. The thing about employees is that your money translates to business value, which is much broader than a single library. This means that when a single library is done the developer doesn't have to think "ok but what's next for this library" and start adding more code. They can stop and move on to other tasks.
Paying for a single library is nice. I support multiple open source developers because I appreciate their work. I recommend everyone does so.
I don't at all believe it's going to help security though.