Personally, I don't see why.

The GTA series is great, but it gets kind of repetitive.  Every game feels the same and the missions seem to be repeated (i.e. kill all *enter nationality* or get this person from point A to point B).

I don't think its a bad idea (they should be able to do it if they just reduce the graphics).

Besides, I think people would be spending more time playing Super Smash Bros. Brawl than GTA.