All of these were lovingly crafted bespoke characters and story arcs, with god only knows how many hours of real human thought put into the story, the setting, and the dialogue.
Bethesda execs don’t want any of that shit. They want a big button that says “MAKE NEW GAME” that they can slap and then a new game that pops out of a slot on the other side of their computers.
The mod community is so vital to these modern games because its real humans having real human ideas that go into them. Business only gets to latch on after the fact, once a DOTA or CS:GO has already fully taken off and left orbit.