I kind of see it as a lose/lose situation for both id Software and Zenimax. Simply put, I really doubt that a Doom game that harkens back to the classic Doom 1 and 2 style of games would sell spectacularly in this era of gaming. At least not "Skyrim well."
There have been some FPS that have tried to mimic the fast-paced/mass-monster killing feeling of the older Doom games such as Painkiller and Serious Sam and those sold well enough but I don't think they were huge blockbusters. And if Zenimax does get their way and makes this into a "Call of Doom" type of FPS, fans of the old-school gameplay of Doom 1 and 2 are just going to absolutely hate it. The one time that id Software tried to do something "different" with a new ip, resulted in RAGE (no pun intended) and we all know how that turned out.
Either way, I think that id Software is pretty much fucked at this point. They really can't please anyone at all in their current situation.
But who knows. Maybe they'll pull a magic rabbit out of their hat and this new Doom 4 game'll be amazing and what id Software needed to keep them from this downward spiral of lackluster games.