Why should Red Hat be expected to contribute to Gentoo? A distro is funded by its own users. What distro directly contributes to another distro if it’s not a derivative or something?

Red Hat primarily contributes code to the kernel and various OSS projects, paid for by the clients on enterprise contracts. A paying client needs something and it gets done. Then the rest of us get to benefit by receiving the code for free. It’s a beautiful model.

If you look at lists of top contributors, Red Hat (along with the usual suspects in enterprise) are consistently at the top.