Good in what way? I'm talking about sells here - In the only objective way I can think of, sales, Angry birds is better than most games recently released.
"Casuals" are what made the DS the monster it is today, with 140+ million in sells. When the DS and PSP launch there were no "Smartphones" in the current sense, The iPhone was announced in 2007! 3 years after the PSP. And it still took some time to the current mobile market to explode in the way that it has. And today, we have
these kind of experiences on these things for a fraction of the price of what you paid for portable games on the PSP and DS. The "Casuals" won't care, we both agree - now the question is, will the "gamer" segment care, and is this segment even big enough to support a console being sold at a loss. We can't know that yet, but if you look at the future, like the
nVidia Kal-El on mobile devices and devices like the Xperia Play and platforms like the PS Suite, it's clear where the wind are blowing even for some "gamers", but not only that - The Vita is now competing with the 3DS on this very small "gamers" segment.