This is probably a very dumb question but I have been a little while into the world of Linux for regular PC's and if I know something is that if something "runs" on Linux, little does the flavor matter, be it Fedora, Debian, Suse, etc.; however, this doesn't seem to be the case on the Raspberry as the official OS is Debian-based but Fedora (25) has still very, very basic support for it. I am aware of licensing and freeware related issues, but there doesn't seem to even be "community" answers to this stuff. I was thinking of stuff like "just copy this stuff here, apply this patch and compile, etc." but I can't seem to find anything. Why is this so and what, as regular users, can do about it?
Edit: Just to be a bit more clear on the main matter of the question: Why you can't just e.g. pull the firmware modules from Raspbian and make them work with Fedora just as you would do with a regular binary (compiled for ARM, of course).