Hi guys, I stumbled on to this thread and agree with what you are saying. I am an avid Sim racer even at my age of 52

I have played most every game there is but not all of them. Now I stick to
iRacing for various reasons. The biggest reason is what all you guys are looking for, "clean racing" I raced GT5 and got level 40 in both disciplines. I raced with a bunch of friends and when we had the right group it was so much fun.
The problems of course were when 1 or 2 idiots would join us and dive bombs and general carnage was applied from them

GT5 does not punish poor driving but iRacing does. They call them incidents, if you go off of the track you get an incident against you. If you hit someone you get an incident against you and so does the guy you hit.
There are 2 different rattings that are effected by your driving which I won't get into ATM. As well there is a license that you need to drive certain cars, starting off as a Rookie and moving up to a D,C,B,A, PRO. This does not happen over night although there is a fast track system where you move up rapidly. Poor driving and you drop back as well.
iRacing is not for everyone but if you are a serious sim racer and are very disciplined then you probably will do good. Don't be mistaken though, iRacing does have it's problems but it is the best sim racer on the planet.