I read your PM, and I see what you're saying. However, the racing you, I, or Joey do isn't professional though you already admitted that. The racing we do isn't what I call racing, but just enjoying our cars to the limit as we're not really racing anyone.
Now, I've done track days as well. I've been out there with the Lambos, Ferraris, Miatas, Porsches, etc. I don't call it racing because, well, from my experience, we are told to not openly race each other as it endangers others. At the track I go to, MotorSport Ranch, we are only allowed to push our cars & we are taught the rules of letting faster cars to go by, by moving to the side. Our rules also state no passing in the corners, straights only. But then again, this is probably why we have no records of any accident on the track.
Either way, my point is that the reason we don't see guys getting bumped at track days is because we're taught not to do it. There's too much on the line. Our lives, our cars, getting kicked out, etc. In short, track days are not a race day. It's just a day to enjoy driving fast. There's no trophies for beating someone else.
In pro. racing though, these guys are used to it. They're actually racing, so sometimes, close quarters are necessary to gain something. And sometimes, these situations lead to hard racing, leading to what happened at the 2007 Sebring race.