I think the OP's point is not that they are to be derided because didn't like the game, I think he's just poitig out how superficial was their appreciation for the "experience" the game provided. Nonetheless I disagree that these people are the COD crowd. It's more likely that the majority are your typical RPG nerds who are complaining that the "art" games are taking their favourite hobby away, because the game is mechanically barebone and it's two-to-three hours long.
I'm actually pretty astouned by the rage this game seemed to provoke. I mean, when I play something unusual and I don't like it, I'm happy to express a critical opininon. I'm HAPPY to discuss it, I HAPPILY say my piece and talk with my peers. I didn't like Heavy Rain, not at all, I found it very poorly executed in every aspect it should have delivered (storyteling, pacing, acting). I'm happy I played and experienced it. Maybe I'm not satisfied but I'm happy I can express this opinion to you. I'm not enraged at all by this kind of conversation, on the contrary I think that the conversation and the awareness within the gaming community may raise the common standard for this kind of games. Maybe I'm just getting... old ;)