@ianbetteridge
It wasn't just the theme of the ad; the actual imagery plays, I think, a part.
If the instruments, paints and so on had been sucked through a giant funnel into the ipad I doubt there would have been much controversy.
It's the wilful destruction of items - items that for many of their users feel almost ensouled or alive - that really gives this a mean, spiteful edge for people.