Fuscha is a kernel and has absolutely nothing to do with this. There are plenty of Linux based Oses that don’t have this problem. (This is even more the case with android since the really hairy stuff like GPU drivers aren’t even part of the kernel.)
The problem is that the entire android user space is built as a single monolithic project that gets forked and closed by the OEM and all of the components have to be updated at once.
IMHO: fuscha will probably make things worse: at least with Linux the code needed to boot the device gets published due to the GPL combined with the monolithic kernel architecture making community projects like cyanogenmod (or whatever it’s called now) possible. I seriously doubt that will be the case with fuscha, it will just get forked and closed like the AOSP components do now (which have the same license.)