I've never really understood OS:es. Why are so many people creating them, yet so few have any success? I've must have seen a dozen OS:es over the past two years on HN, most developed by people having no confidence in calling it a serious effort.
Why care about OS:es when there is no room for anyone on that level of abstraction apart from a handful developers at MS, Apple and Google?
It's usually a learning project. The same way tons of people implement web servers but ultimately use something out of the box in production.
https://github.com/klange/toaruos << example of a hobby OS taken farther than most I've seen.