Maybe I'm just being old fashioned. But they cost so much money, and that's before you even get the games etc!
Purely from the money PoV, I was so surprised at how many of the 5 and 6 year old kids I was looking after had today had them.
From a being old-fashioned PoV it seemed so boring that they'd gone away to a different place and they were still playing computer games. I know teenagers do this all the time, but it seemed so unimaginative for five year olds to have to stick to the computer game rules all the time.
On the other hand I met some really sweet kids! I forgot how much energy little kids can have.