StingingVelvet: Dude their games are huge on console and I bet a lot less PC players mod than you think. This idea that Bethesda games are only popular because of mods is silly.
I'm having a hard time finding a vanilla playthrough on youtube. Makes you think, wouldn't you agree?
I've played both Fallout 3 and 4 without using mods. Felt no need for further modifications. Also, I was able to properly assess their work. Which honestly left a lot to be desired.
I agree, their popularity stems from different factors, but the ability to mod the games may very well be a major selling point. As I see it, the first and foremost is the open world aspect. Instead of focusing on creating compact, rich, believable, well-written worlds, Bethesda ends up with large, underutilized maps, in order to fulfill the customers' needs: roaming around, doing who knows what. Shooting mutants, raiders and something else perhaps.
Several locations in Fallout 3 made little to no sense, like Dukov's Place, The Republic of Dave, or even Arefu just to name a few. Do they really expect me to believe that an old man with faulty vision is able to defend a settlement placed on top of a crumbling overpass? And how about Big Town, Canterbury Commons, or Girdershade?