The increasing division between core and casual gamers actually makes a lot of sense, and fits well with Shamus' article about how the GPU (and the heavy hardware required to play games) is killing/changing the game industry.
All those grandparents and kiddies who have cheap PC's to check their email can't run Crysis, but Peggle does just fine.
In the words of Yahtzee "It all fits together quite nicely, like furious bloodstained sticklebricks."
I've never really understood why the division needed to exist in the first place, I don't remember anyone getting this up in arms about Solitaire back in the 90's and it's the most popular video game to date.
To me the core gamer is becoming the equivalent of a hipster. They define themselves by video games not being cool, by its anti-social nature and its eccentricities. As games become more mainstream with casual games, they pine and moan like a hipster realizing that his favorite band is becoming popular. The identity of being a "gamer" no longer means anything because now everyone plays games.