This site is great and contains so much information. Unfortunately it's hardly meaningful part of knowledge you need to write any modern OS. Unfortunately, because it's realy good fun to do stuff like that. It's quite hard to enjoy for a long time creating stuff that even you would not use.
I don't know, I've had a lot of fun making stuff I wouldn't use. Designing and implementing things (programming languages rather than OSes in my case) is more fun than actually using them :).
Not planning to use your project also gives you a certain freedom. You can do all sorts of crazy and impractical things just for fun. My language lets you change the precedence of operators at runtime. It's a stupid feature that would only cause misery in the real world, but I'm not writing my project for the real world :).
That said, it is also fun to write things people actually use. In fact, just having users or using your own program yourself makes up for having to deal with boring issues, annoying corner cases and reality in general.
