The appeal of these Bethesda games has a lot to do (in my opinion) with immersion - which is a function of the graphics and game physics. It makes them fun to play around with even if you get bored with the story and/or everything getting somewhat repetitive (like exploring the same caves over and over again in Skyrim to get to the last skeleton guy so you can read the dragon word and get a sword that looks like all the others but has 40 charges of fire damage). To the extent these element get too far behind the curve vs. latest and greatest, I think it will hurt their games and they will sell fewer copies. Immersion requires state of the art visuals.
But what other games provide this open world immersion that are better? In the fantasy genre I can't think of anything other than Witcher, but you have to play Geralt, which is different, and that can leave a gamer feeling the need to fire up a Bethesda game to role their own character. I also think some of the awkward movement in this game engine is easier to tolerate when you are swinging swords and axes vs. shooting guns. So maybe that bodes well for the next Elder Scrolls.
But in the post-apocalyptic gun fighting genre, for me the clunky-ness is more pronounced, and I think there is more competition with first person shooters or maybe even some of these super realistic combat games. So I wouldn't be surprised if this Fallout 4 title disappoints in terms of sales due to the genre and outdated look. Could easily be avoided with a great story, but I wouldn't bet on that given Bethesda's track record in that department.
