Sorry, but I was never a casual gamer. My first real gaming experience started with Doom and Wolfenstein 3D.
Regardless, I agree and disagree with you on some points. Yes, most gamers of today who recall the "glory" days of NES and SNES are mostly recalling games that could easily be called casual titles. Most platformers of those days were overly simplistic in their gameplay and tended to rely on ridiculous amounts of repetition.
However, I don't know where you get the idea that any of the new wave of casual gamers is going to actually jump to more involvement with gaming. Most of the new casual gamers, (moms, wives, grandpa, etc.) won't ever make that jump to more complex and superb games because they just don't care enough. They view gaming as an occasional diversion, not a worthwhile hobby. The only people I can see as making the jump are kids in the age range of (3-10), which the Wii is very popular with. The kind of gamers that the Wii appeals to will continue to buy shitty shovelware titles because very few of them will make the jump to actually try and find good games.
Does the new wave of casual gamers have shitty taste in games? Sure they do. They don't have the experience necessary to weed out the good from the trash. This also kind of occurs in the "hardcore" market occasionally. It's the entire reason why a mediocre game like Halo became so damn popular.