I don't know enough about the levels of contribution to either to make a strong comparison, and I'm more than willing to grant IBM and Red Hat make much larger contributions to Linux than Apple does to FreeBSD. And I sympathize with the desire to have more contributions. The "how Apple treated BSD" phrasing sounds like there is more active bad treatment rather than not contributing enough. Maybe the hiring of Jordan Hubbard is considered active bad treatment? (Honest question)
[0]: https://opensource.apple.com
[1]: https://wiki.freebsd.org/Myths#FreeBSD_is_Just_OS_X_Without_...
That's Clang/LLVM compiler that gets them off GCC's GPL codebase. It also allows them to keep more extensions proprietary if they choose. It's been beneficial to the OSS community but I'd say it's barely altruistic. An exception rather than the rule.
" The "how Apple treated BSD" phrasing sounds like there is more active bad treatment rather than not contributing enough"
Helps to remember that it's how a lack of contributions is commonly phrased. Freeloading is probably the dominant model for both users and companies far as FOSS. It's just how they word the gripe. I agree they should probably use clearer phrasing for others not deep into this subject matter.