In fairness to the interactivity of Doom3, remember that in that old e3 video you saw boxes and things being knocked off shelves by gunfire. So some of that interactivity is there.
Secondly, Carmack may be an engine god but he's clueless about what gamers want. For example, he initially ruled out the rag doll physics for dead baddies because he thought it was just a gimmick. It was eventually put in because "evidently people really wanted it", which seemed to surprise him. Now, months later, the physics engines are what everyone is salivating over. Surprise, surprise.
Carmack wants photo-realistic graphics; I want a pseudo-realistic WORLD.