"I find it hard to believe that the life expectancy is as long as two years..."
"I find it hard to believe that the life expectancy is as long as two years, since that’s about how long the average corporate laptop lasts when given to grownups."
a)just because a corp replaces things every 2 years, doesn't mean they only last 2 years.
b)You've not been in a school have you... they often have old PIIs chuntering away, struggling under all the 'security' software (that stops you changing the desktop wallpaper but happily lets you view hard porn), on which kids are supposed to learn about computers. Then the teachers might have 4-5 year old laptops.
The wife's school has some iPad 1 units that haven't broken yet.
For very young kids I think tablets are a great resource, you do not see 2-3 year olds able to use keyboard+mouse but they are very easily able to learn how to use an iPad (scarily so, almost - weird to see a kid who can't talk but knows how to find Cars in Video app).