This from Reuters:
"Scott Forstall, a long-time lieutenant of late Apple co-founder Steve Jobs, was asked to leave following years of friction with other top executives and his recent refusal to take responsibility for the mishandling of the Apple's much-criticized mapping software, people familiar with the situation said.
Sources said Forstall refused to sign a public apology after Apple's mapping product, which displaced the popular Google Maps on the iPhone and the iPad in September, contained embarrassing errors and drew fierce criticism.
Instead, Cook signed the letter last month."
takes guts to stand up to the mob and say it was your fault, Forstall at one point was being touted as "the sorcerer`s apprentice" long fall.