I don't think that's true. Many members enjoy non-cub art as well and it's not hard to find artists with 2500+ watchers and no cub art.
What is true is that a lot of popular cub artists moved here from other sites, so a lot of the popular art is cub. And it's easier to get faves for cub art with lower quality, because there is so much non-cub art on other sites too.
I don't think that's true. Many members enjoy non-cub art as well and it's not hard to find artists