Many of the games that are ported to Linux can be found DRM free onb other sites, like Desura, GOG and the Humble Bundle store. Most games are on Steam since that's the best way to get sales on PC.

There's a massive difference between a recorded frame and a rendered frame. Movies are shot at 24fps and get natural moron blur that blend each frame. Games don't get this, as each frame is rendered sharp. Therefore you can't compare movie fps to game fps.

This might have been an issue if TESO was a sequel to the single player games, developed by the same studio. However, the game is set in an earlier era, the one that ends with Tiber Septim conquering Tamriel, and the game is developed by ZeniMax Online Studios. Basically, it's a spin-off that's backed by the same publisher. There's no reason for Bethesda Game Studios to stop churning out more TES single player games.