Apple includes Rails with [OS X] Leopard (2006)

It's a fairly common problem. There's a model adopted by many open source projects that you don't have to maintain ABI (or even API)[1] compatibility across major versions, which is fundamentally incompatible with platforms where deploying software as binaries is the common or default approach.

The result is that the OS gets permanently stuck on an old release, so if you want to use new features you have to include your own copy of the library.

This isn't intended as any kind of value statement for the approaches, or who is or is not being reasonable, it's just intended as an objective statement of what happens and what the result is.

[1] [edit: added this entire footnote] For ABI here, I'm including behaviour/semantic changes that break dependent software courtesy of Hyrum's law. It sounds like that's what the PHP issue was.