I've been participating in full-contact kickboxing for 2 years. My spouse kickboxes, and I have two teenage boys that kickbox. You bet - all minor, no concussions or brain damage. Ny son's have suffered more frequent and serious injuries from bicyling, skateboarding, and downhill skiing than from kickboxing. And my worst sport's injury occured playing softball.
Bottom line is all sports carry a risk to the participant.
We know we are going to get hurt, know what it feels like, and know the consequences. Unlike the downhill skier who knows there's a chance of getting hurt - but dosen't really understand the consequences until he hits the tree and breaks his neck, we go into our sport with eyes wide open. I think that's un-nerving for those who try to forget or minimize the risk of their sport whenever they participate in it. It probably won't. Boxing and kickboxing are no more dangerous than any other sport.