this behavior in iOS drives me absolutely insane. and somehow apple gets away with it when it's just as intrusive as the shit microsoft and facebook do.
in that interface, and in mac os x as well, it seems it will upgrade at a certain point anyway, no mater what you choose. i always answer remind me later, and i will often come home to my macbook pro or iPad having been restarted due to an upgrade. the macbook is particularly annoying when it upgrades because it leaves about 10 minutes or so of stuff left to do that isn't triggered until i go to unlock my computer. so i come home having something urgent to do, try to wakeup and login to my macbook only to find it needs to finish the installation i never chose to do (or at least never intended to do). and still apple gets away with it.
in that interface, and in mac os x as well, it seems it will upgrade at a certain point anyway, no mater what you choose. i always answer remind me later, and i will often come home to my macbook pro or iPad having been restarted due to an upgrade. the macbook is particularly annoying when it upgrades because it leaves about 10 minutes or so of stuff left to do that isn't triggered until i go to unlock my computer. so i come home having something urgent to do, try to wakeup and login to my macbook only to find it needs to finish the installation i never chose to do (or at least never intended to do). and still apple gets away with it.