Your opinion is that people are BELOW you for playing differently and not needing extreme challenge to enjoy things.
Jobs and roles have been simplified and the playerbase has grown. One could argue this means this is better for the continued survival of the game.
So devs continue to focus on content for the more profitable and consistent playerbase with a more manageable appetite (bleeding edge challenge content consumers require CONSTANT new content).
Does 14 promote a "culture" of mediocrity? No. It caters to the tastes and habits of a large player base. It makes the entertainment available to those who wish to engage in it.
And now, pending your edit I guess you're just calling people fat now. .. probably not your intent but it seems like a Freudian slip.