For a hobby OS .. nobody is stopping you. I have my own hobby OS where everything is custom, I don't even have a standard C library, I made my own, I don't copy posix conventions, everything is just implemented as to what makes sense to me. I never understood the people that go through all the effort to work on their own OS, and all their work is to just create a linux/windows clone from scratch. Of course even accomplishing that is a huge achievement, but if you're going through all the effort, why not do something different?