The majority of Nintendo's DS Lite demographic is the casual non-gamer, who barely know how to enter the directions to GameStop into their TomTom and buy Brain Age 2, well enough order a flash cart from the Internet. What kills DS software sales is that those folks won't buy crap like Contra and Etrian Oddysey, because they don't even know what they are and the demographic most likely to buy said titles will buy a R4 cart.
The PSP on the other hand is just a crazy piracy device, at this point. I would speculate that the majority of folks who purchase one from my store, do so with the sole intention of hacking it. Would I dare say some ludicrous number like 90%? Nope, but more than half, for sure.