Nah, the Wii's more like the dog locked out of the house on a rainy day.

Actually the Wii is more like the pretty girl on the schoolyard that all the 'popular' girls ignore because she gets all the attention elsewhere.

While true, I think the context and timing of each release played HEAVILY into that.  Vesperia PS3 came right in time to perfectly ride the Slim relaunch and momentum (and was arguably the first "big" game to do so), had fantastic word of mouth from the previous 360 release (plus enough new content to ensure every hardcore Tales  fan rebought it), and launched alongside the First Strike film (with TONS of co-promotion).  Graces meanwhile launched a week before FFXIII (something JP retailers even called suicide, and chiefly blamed the weak launch on) and was almost unplayably buggy (to the point where Namco had reissue new discs... 3 months later).  In Graces favor was a new game (from Team Destiny, arguably the more successful of the two Tales teams), and both games got system bundles (as did Vesperia 360 originally).

I still think timing was the biggest factor though.  Had Vesperia PS3 and Graces each launched six months earlier or six months later, I think they'd have probably sold around the same (say ~250-300k).  Had Vesperia PS3 launched a week before FFXIII, it might not have even outsold the 360 version.