It's good to have a niche, but it's even better to write out your experience. Writing what really motivates you.

I think one can not write just for others or for what audiences need you to do. Instead, one can write about what he wants to share with the world and pull the audience to read it. Proving that there is always something to write for rather than writing for a niche that's already known. My Eng is not good, but I believe my point is clear.