They should have created sub sections for most things (dozens of topics fighting for about 50 spaces tops is brutal and part the reason why most of my topics don’t get any replys; in addition, no need for the Mercy gigathread).
As for custom Hero concepts in general, I have found there is a lack of attention to them based on my own experiences with my Hero Concept Lab (done pretty well considering the topic area, but still pretty slow most of the time):
Not sure whether this shows a lack of interest from the community or just finding it hard to get noticed amongst all the “Nerf ___ Hero!!!11!!!1” topics. One of the few that seems to have gotten off the ground any decent amount is this one:
Anyway, hope you can get more attention in the future!