It's worth looking a bit closer at some of these objections; "the product is mature from the start....". Translation: "it works right away". How is this a bad thing? It certainly doesn't follow that it becomes obsolete any quicker.
"Airlines customise/optimise extensively.." Actually mostly not the case other than for cabin detail and galley fit. Even there, the only time in my own experience a big change was demanded, it was a shambles. Cathay originally demanded their 747-400 with analogue instruments for commonality. That was swiftly canned when Boeing told them how much more it would cost!
What would an iPad look like built to a military specification? Obviously it would have to withstand nuclear attack and work underwater and would probably be about the size of a piano.