Except you can't compare the situations at all. The reason id abandoned Doom was because Doom started to fade in popularity. So first off, you have to assume a world in which each new Doom game was even more popular than the one before it to even begin to make that kind of comparison. In other words, you have to imagine the fanbase being completely different, as well. So that means, Final Doom would have to be the most popular of the PC Doom games, overshadowing Doom 2 and blowing the original completely out of the water. And then, Doom 64 would have had to absolutely destroy Final Doom in terms of sales.
My point, which I actually failed to make, was that Doom was kind of abandoned by id, but they keep churning Call of Duty games out. COD MW3 was in most ways a step back from 2; no co-op missions and the survival mode just wasn't that good apart from one or two maps. Yet they keep on hyping it and churning it out. What would have happened if id had done that with Doom and kept hyping each new game like they hyped the original?
So let's work from there.. Even if that were the case, we still have the fact that id is a (relatively) small game developer, not some gigantic publishing powerhouse. This grants them a little more freedom to follow other pursuits, without profit having to be their bottom line. So who knows? Maybe even with Doom 64 outselling every other version of Doom known to man, maybe even then they say, "Let's focus our resources on developing new ip rather than constantly rehashing Doom."
But let's say they did just keep making new versions of Doom. Actually, I think I might have actually liked to have seen a version of Doom built on, say, the Quake engine, and then the Quake 2 engine (I'm ignoring things like YPOD for the moment). Well then, even then, the thing you have to remember is, this isn't them forcing it down our throats. This is us asking, no begging for more, and literally throwing money at them. However long the development of new Doom games lasts, it depends on whether or not people keep buying them.
I don't mean to harp on that point, it's just something that a lot of gamers don't seem to get - they really do have the final say in what games get released. They vote with their wallets. This isn't directed at you, MajorRawne, just something that really bugs me. And it's like, no one has the balls to attack the gamers themselves. No one's willing to blame the gaming public. It's always the evil corporate overlords who dictate what we play, never the fault of the players themselves CHOOSING to play the same crap every year. Why do people keep buying CoD games? That's the real question here. What's the appeal? Why do they sell so well?