I think the problem here is you must be some neck beard room hermit who never leaves home. It's a portable gaming machine. It can be anywhere. On a trip, on a flight, in the car, at your friends house, on the beach, in the park, etc etc etc. It's meant for a little bit here, a little bit there, and switch to this right now. As exemplified by the pause anywhere features all modern handhelds have had.
Plans change unexpectedly, things happen suddenly. When plans change, and I'm either waiting or bored I might just want to pull out that portable gaming machine. However today I'm in the mood for Megaman X, so I'd like to play that, but it's on a previous system. I'm pretty sure I wont be, or have the time to go, driving back home, exchanging systems, and driving back every time.
If Nintendo can get it right, Sony is surely capable of it too.