I blame achievements and multiplayer being considered the "real experience."

Achievements turn what used to be just self-imposed restrictions and goals into an external thing acknowledged by the game. Before, something like a pacifist run or no potions run was just something that you did for fun as a challenge. But once achievements became something explicitly acknowledged by the game, there's the question of legitimate achievements and illegitimate achievements (achievements that you got because you entered in cheat code which made getting them much easier). The easiest way to solve this is to just not have cheat codes, which leads to stigmatization as cheat codes are no longer part of a typical gaming experience.

Multiplayer just made people try to judge singleplayer game with multiplayer criteria, so people think entering in a cheat code is the same as running an aimbot. It's also the reason why people obsess over balance even in singleplayer games where balance isn't even that important. Weapon A being better than Weapon B literally doesn't matter if the game acknowledges that Weapon A is better than Weapon B, the least clumsy way being through lore. There was a time when singleplayer was the authentic experience and multiplayer was just something tacked on. Now, it's the complete opposite.