Most people use an OS to do things, not to do an OS.

It's like with cars: There are some car nerds who tune their own engine control parameters and replace broken transmissions and engines themselves.

But for most people a car is used to get to work (or other places) not to play with them.

And while there's nothing wrong with using an OS as a hobby because you love debugging things, it would be strange to expect that everyone wants to play with an OS instead of using an OS to accomplish something.