In my experience, a new toy c compiler pops up roughly once a year.

https://github.com/Wilfred/babyc http://www.sigbus.info/how-i-wrote-a-self-hosting-c-compiler... http://zserge.com/blog/cucu-part1.html https://c9x.me/qcc/ https://github.com/alexfru/SmallerC

Sure, and most people do this as an exercise, whether it's to learn how to write a compiler, or to see how small they can make the compiler, or something like that. No one does it because they really have a strong practical need to.