So why do you think that adjustable difficulty, through blunt difficulty selection or more detailed settings menu for specific aspects, that are tied to difficulty isn't also an accessibility option? And if it wasn't something you had to tinker with, you'd get the exact experience you have right now, why would it be a problem? People have already told that they've tinkered with the games' difficulty on PC and their experience improved. So why not open up something similar to all the platforms, so more people could have fine time with the games. As of right now they aren't.
Because it alters the core design of the game. Its fundamentally a different game with those changes. Its like asking Twilight Struggle to be played with an open hand.