We had this discussion awhile ago. It included links to real articles talking with players all about it. The bottom line was very, very few football players where cups, at any level.
I played catcher for many years of my youth. Wearing a cup was so incredibly uncomfortable. Wearing it while running bases was horrible, but very rarely did I have a system that could be easily removed, or a place in the dug-out where I could go about it without flashing everybody. I always thought it was crazy to expect athletes who have to run to wear a cup. Turns out, they don't.