... if Apple reject, then your stuffed. All that investment wasted. There is no alternative ( I'll ignore jail breaking, because its unofficial).
And the customers have invested too since they're locked in by ETFs payable to AT&T. It's like signing up for a 21-day "all-you-can-eat-and-drink" cruise round the mediterranean. But on day 2, the captain takes meat and booze off the menu and you're eating salad for the next 19 days.
Folks blithely stating that iPhone customers 'simply' go elsewhere is a bit like the captain suggesting you swim for it. In mid-Atlantic.