They may have committed to launching Maps with iOS 6 early on, and been so pissed off at Google that they burned their bridge (that is, their iOS 6 branch which

They may have committed to launching Maps with iOS 6 early on, and been so pissed off at Google that they burned their bridge (that is, their iOS 6 branch which retained Google's maps). So in that case, the choice in front of Cook would've been a) launch iPhone 5 with shoddy maps and iOS 6 or b) launch iPhone 5 with iOS 5, or possibly c) don't launch iPhone 5 and watch the stock price crater.