I've been using vim for years, but I completely disagree with your statement. I rarely find the "," key useful, so to me it was a no-brainer to switch to using it as the leader. I just have ",;" mapped to the functionality that "," used to do.
I use ";" all the time, but searching backwards just barely comes up. Usually, I'll hit "home" and then repeat my "f" search if I need it.