One thing that I has been wondering is while there are relatively large amount on alternative operating systems (and some are quite awesome like Haiku), still most Linux distros seem to be repackagings of classic gnu/x/(gnome|kde) apps. I find it hard to believe that these days high level userspace innovation is so heavily bound to kernel. Why don't we have more diverse Linux distros instead of having diverse collection of complete operating systems?

Especially for hardware support it would be kinda nice if more projects would use a common kernel instead of writing one themselves, and I find it also hard to believe that its easier to write a new kernel (that actually works in a range of hardware) compared to modifying an existing kernel to fit the project.