Its not the system that's the problem it is the people. Dungeons are developed with a certain gear level in mind. Sure some people are skilled enough to get away with less but most of us aren't as much as some want to claim otherwise. The problem comes in when you have someone trying to join a group for an entry level HM and certain types of people thinking unless you have all end game top tier gear you aren't worthy of the instance. THAT is where the problems will start. Not that they are now blocking people who try to bypass the progression system already in place.