its a two part question: is content that is not easily attainable by a lot of people an aspiration or is it a wall? The second part imo is more important, which is how will the developer react to how people react?
Historically in MMOs over the past 5 years, when people hit "the wall" (different for each person) they quit. There is just sooooo much stuff to do out there, there is no reason to try and get better or make new friends or whatever, you can just hop onto the next thing after having played 30 or 60 days. So if/when a ton of people cancel their subs, how will Carbine react?
Will they be like every other studio and make a bunch of crazy kneejerk promises and changes that make little sense, to try and stem the tide? Or will they be happy with retaining X hardcore raiders players and their groupies (for lack of a better word) and cater to them?
if they stick to their design ideas and are happy without a million subs it sounds great, but given that they are owned by NCSoft and the history of MMO devs its hard to believe that will happen.