But it's so simple to understand.
If you can't do it = you're not ready.
If you're not ready = you won't clear it.
This goes beyond the whole "let the player decide". You're basically saying that a level 10 player should have access to Aurum Vale regardless of the in-game process to build you up to that point just because it has to be the player's decision based on their curiosity rather than their skill, gear and progression level.
The live letter said especifically that this content is not meant to "carry" or "get carried".
I'm not even a hardcore raider but really, not everything in this game has to be accessible to everyone because that trivializes content for those who want really dificult challenges to face and have the skill to overcome it.