I think one of the reasons might be that Western gamers, in general, don't really enjoy handheld games that replicate the home console experience.They may still sell decently, but never truly take off.It's a different case with Japan, since they've been favoring handhelds for quite some time now.
One of the reasons the DS was so successful was that it wasn't `trying to be a home console on the go`, it had its own games that were a perfect fit for handheld gaming.
Games like Uncharted, God of War, Resident Evil, 3D Zelda, 3D Mario, etc...for handhelds might make some gamers drool with anticipation, but they're not the recipe for success in the West, as far as handhelds go.







