Linux came into being as a fun hobby project. It was successful because it gained traction with the wider community and got huge commercial backing because it was vastly superior to most of the alternatives from a user perspective ("oh hey, I can run my web servers on this 100% free kernel plus the GNU userland and have a mostly good server for zero software cost on commodity hardware"). But today, Linux itself exists, and while there are underlying technical changes that could improve on it, from an end-user perspective (especially potential commercial backers) anything else would be barely different, if they could tell at all. You'd need some huge compelling advantage - that a user cares about, nicer code and 5 bugs a year instead of 10 bugs a year isn't going to cut it - to actually gain any ground.

Maybe I will write a TODO app in Rust, should it be on top of HN because is some unoriginal,incomplete,bug filled,toy stuff just because the reason is written in Rust? 1

My assumption is that all titles with Rust get blind upvotes, sure a new kernel is cool but would be more cool if is more then someone toy project, this should probably be posted and upvoted in Rust forums so it gets support from the fans and hopefully the Rust guys will decide what kernel should they focus on and stop promoting every student weekend project here.