Blast from the past, been away for 8 days visiting my girlfriend in Sweden.
Are you suggesting that the core and casual markets aren't separate or that there are so many markets that this is irrelevant, I'm having trouble deciphering your post.
If you suggest the former, I must disagree strongly, you cannot suggest that Angry Birds and Gran Turismo 5 appeal to the same userbase. Farmville and The Witcher, anyone? Doodle Jump and Valkyria Chronicles?
If you suggest the latter, I must also disagree. At least as far as gaming goes.
If you claim either of the above, which you appear to be doing, you shouldn't be pointing fingers and accusing others of not understanding the video game market.
What I'm suggesting is that there's no distinct separation between the two "markets" as the hardcore assign. There are people who like both, and behaviours are not particularly different between them. There are people who behave like any other core gamer, but their game style of choice is games like Angry Birds. There are a LOT of people out there who might pick up two or three games for their console in the entire time that they own it, and one of them is GT5. And there are people out there who love both games equally.
In short, the imagined distinction seen by the hardcore doesn't exist. What does exist is a spectrum of preferences and play styles that make the market far from the simplistic form that the hardcore like to assert. You have people who will buy the new CoD every time, but otherwise only own one other game. You have people who own all of the Just Dances, Wii Sports and Resort, Wii Fit Plus, Tiger Woods golf, Rayman Raving Rabbids, and ten other "casual" titles, all at once. And some of those will also own Resident Evil 4, No More Heroes, and Goldeneye 007.
In my own case, I own such games as Red Steel (1 and 2), World at War, No More Heroes, Metroid Prime, Twilight Princess, and The Conduit. I also own Wii Sports Resort, Sonic and the Secret Rings, Wii Fit Plus, Rayman Raving Rabbids 1 and 2, Super Monkey Ball: Banana Blitz, New Super Mario Bros Wii, and Tiger Woods 10. Note that this is just a selection to demonstrate my point, I own quite a few other titles of both "types".
The message here is, stop trying to segment the market. It's nowhere near that simple.