Even if all you were doing is "mastering the GM", which of course, is silly, you'd still be mastering how he deals with combat, exploration, religion, politics and all the social interactions of the world, many of which (like henchman, hirelings, followers, strongholds) have rules in earlier editions to interpret, judge and implement.
In 4th, you proceed from My Precious Encounter to My Precious Encounter, handing the GM your magic item wishlist when you level.
It's an obvious false equivalency, otherwise WotC wouldn't be holding hat in hand claiming they went too far in one direction of play.