You are spot on in what you say. By diversifying voting it will help the whole platform. Right now there seems to be a very narrow spectrum of content that gets upvoted. That may end up putting a lot of people off. The more people who start to do as you suggest the more the platform will get actual REAL sustained growth.
I actually consider myself one of the few lucky ones that made it above 10k. It certainly is easy to get stuck in the mainstream cycle.. but yes everyone has their own interests.. it only makes sense to do what you can to help the niches that you're interested in flourish :)