The normal content you refer to is story content and is not , never has been designed to be a brick wall.
You DO NOT tune content to be that hard that you cant finish the story, as this is a story driven MMO..all you will do is have people say yeah this is nuts and walk away.
You have savage, you have extreme, you have criterion which is midcore, you have ultimate which has turned out to be little else than a cheat fest. ( You heard me, If you cant win without cheating you dont deserve to win at all )
The game is not and should not be designed so "only the worthy" get to see content THEY PAID FOR.
WOW did that, the results of that dogs breakfast speak for themselves.