First of all, if someone is looking for cutscenes and a big background story and cinematic effects etc. classic Doom is definitely the wrong place. If we compare silent-movies from the early 1920s with current movies, then we will of course see a huge step forward in terms of technology and effects etc. but that doesn't mean these older movies suck or don't do their job anymore. They still fascinate and are impressive in their own way. It just depends on what one wants.
But to get back to the original topic: Immersion. I think immersion is not very depending on technology, at least I see it like that. You find many people who love and play "retro" games (old ATARI, NES games) and find them more appealing than modern games, and also more immersive. The lack of 'perfect' graphics and minimalistic design makes it possible to create the missing content in your own head, in your fantasy (like children who play with sticks and pretend to be a knight). After all, it is a game, if children are playing with LEGOs or adults are playing with video games, it is basically the same.
In many games (or movies) I simply don't want to know everything, because I know, that whatever the creator would bring up, couldn't beat my own imagination, how I picture it. And I think this lack of a deep story and cutscenes etc. made Doom so universal, almost like pacman. You can simply pick it up and play! Concerning the demons, hell, etc. you can make your own ideas and thoughts about how and why everything is happening as it happens in the game. And after all, what matters at the end of the day is the gameplay, if it is bad, nothing can make it up.
So I think that it is pretty subjective what actually 'immerses' you into a game. Again, it just depends on what one wants.
(Oh, and of course the top gameplay in Doom, which simply doesn't tread one as a moron like Call of Duty games do. I had to state that!)
