I think Jeff hit the nail on the head regarding the Vita's lack of backward-compatibiility.
How can anyone be upset that the Vita doesn't play PSP games? Yes, backwards compatibility would be a nice bonus, but the idea that we somehow deserve to have an old game we purchased instantly work on a new console is very confusing to me.
When I bought a DVD player, I didn't complain that my old VHS tapes wouldn't work on it.
I think backwards compatibility is a great bonus when it happens, but the idea that gamers somehow deserve to be given a new free copy of a downloadable game is silly. As Jeff said; when you buy a game, you are paying for 1 copy of that game that works on the console it was made for. You are not entitled to anything more than that, in my opinion.