All of those people that want stuff like Mass Effect already have a PS3 or 360 because those games are already on those systems. And those types of games - massive, graphics-intensive RPGs - are done better on those systems. I never said that you couldn't do RPGs on Wii - but there's a reason why Final Fantasy XIII isn't being done on Wii. Whether or not you think FFXIII is a good game or a bad game is a separate issue, but if you want those types of games you don't own a Wii. If you do, you're kidding yourself because those games aren't going to come out. You'll have Namco making Tales of Awesometasia 3 instead.
If that's your thing, that's cool. But if the Wii is such a no-brainer, why didn't Square-Enix make DQ IX for Wii? Because RPGs aren't a proven commodity on Wii, while they are for DS. Also, DS development is much cheaper, and the DS is ubiquitous in Japan (whereas the Wii is currently being outsold by the PSP and DS on a regular basis), so you have a guaranteed massive payoff. The Wii is considered a risk right now for anything besides family or casual-skewing fare. That may very well change, but that's how it is for now.