The dumbing down is hardly even specific to Bethesda though. Hell, look at the state of the grandfather of RPGs - D&D. 5e's tolerable but only because the backlash to 4e was militant enough that Paizo saw money and hopped on it with Pathfinder and Wizards couldn't let it stand. Even with 5e though there's this continuous drain on choices - no more real skills (by which I mean skills having the ability to either specialize or dabble in. Its all or nothing) - and verisimilitude - the community is still encouraging the 'reskin' stuff from 4e even when it makes no sense - and rewriting of well established lore characterizations. Some of it works for stuff like Hags and Giants, but Kobolds went from being murderous pests to being goofy jokes - along with their god Kurtulmak (a goddamn god of a mining culture getting stuck in a cave for eternity) - and that's not even mentioning the taints carried over from 4e to make Tieflings and Aasimar more 'grimdark' or something because a dev thought they were 'boring'. I haven't looked at GURPS recently, since my group doesn't play it, but I can guess its being simplified if its been updated too. God forbid anyone take 10 minutes to add or try and see why "fluff" and "crunch" aren't separate but extensions of each other in a structured world.
Over-simplicity rules because any sort of rigor on things is seen as overly restrictive, taking the power from the player, and frankly infringing upon a character's 'uniqueness' or 'power'. Which I can stand to a point, I can dig weaker monster characters, but only when the world reacts accordingly, but half these people get annoyed when they characters don't respond how they want or show personalities they like. All because it interrupts their power fantasy. Apologies, that turned into a rant.
So far as the commercialism goes it'd be almost clever if it weren't so obviously accidental.