I did KM for a year. Kicks to the crotch are certainly normal here. I never had any problems, because those guys were careful even if everybody had a jock strap on.
Now I moved to another place and found another KM club there. Here they are somehow more harsh. They do not hesitate to kick your private parts a little harder. This hurts even with a jock strap on. The pain is not unbearable but still every kick hurts. They even somehow find it to be amusing and are making jokes about that.
I would not consider myself a wimp, I already did some other things (kickboxing, taekwondo..). But still I wonder, does this somehow affect your potency? I mean those guys seem to be professionals and do not seem to care. So they either must be pretty confident that this does not have any longterm side effects on their sexual life or they simply do not bother.
Any experience? Btw, by habit I somehow tend to block kicks like this with my knee so they get hurt on their feet every time. They must be hating me for that.