Main Scenario Restriction Bloodstorm - Very Very Bad idea.

[Reynhart]

This is a pay to play Massive Multiplayer Online game. Gameplay should always come first. The second someone hits level cap, they should be allowed to gain access to endgame raids/Trials (as chances are the MSQ will have nothing to do with it).

Gameplay =/= Endgame.
Every content is part of the gamepay. Besides, to have access to the "endgame" you also need a minimum gear requirement, that you probably won't have "the second you hit the level cap", and unlocking requirement. The second you hit lvl 60, you won't have access to Creator or City Of Mhach.

Without doing the content, you'll also won't have access to most daily roulettes, anyway, so you're just hindering yourself in the end.

My ~300d playtime consists of maybe 200h of "story" and 291,5d of "no story".
So no, the base foundation of this game is not the story.

Consdering that without this, you wouldn't have access to anything, yes it is. Being the base never meant that it would take most of your playtime to do it. And, in fact, I really doubt the story took you 200h, considering each patch gives, at best 2h of MSQ, dungeons included. (And I doubt 2.0 and 3.0 gives 180h of story combined.)