Most games are casual... Mario, Zelda, Wii Sports, GTA, Gran Turismo, Halo, Call of Duty, Madden, Guitar Hero, Final Fantasy, etc. All of these games and basically most other games that have any signifficant amount of sales have a primary audience of "casual" gamers. Casual gamers being people who know very little about games past what they see on TV.
Believe it or not, 90% of gamers are casual on all platforms. 60% of PS3 owners don't even know their console has blu-ray. Do you really think these people are "hardcore" or even "core" gamers. Hell no. They are people who went "Oh cool, that thing plays Madden and GTA give me one of them!"
Gamers are casual. This is an industry populated by people who treat it as a casual hobby. People who walk into a Gamestop and buy something because it looks fun, or because it had some totally awesome commercial on TV a week ago. This is the majority of GTA players, the majority of Mario players, the majority of every single popular game in existence. The majority of gamers on all platforms know little to nothing about video games. The people who bought GTA in the first day may not be by majority casual, but the other 8 million people who are going to buy the game over the next 2 years sure will be mostly casual.
This is our industry folks. Reviews don't matter. Your opinions don't matter. Crying on a forum about one system being casual, gimped, kiddy, etc. doesn't matter. What determines sales and popularity of 95% of big games is nothing but hype, commercials, and and the popularity of the console the game is on.
Deal with it.