If Tim Cook does his job right: There will be several of those underling heads rolling, either by Tim himself or some one who takes over Forstall's area. (And which one of those two possibilities will tell us a lot about Tim Cook.)
That might be an excuse Tim Cook himself can reasonably use, but not the exec directly responsible for the development of the new Maps app. He simply can't say he was getting information from a small number of direct underlings - he should have been in the trenches talking to the developers, testers and beta users and getting feedback directly.
He was putting his reputation on the line by being the original public presenter for the new Maps, and if he was prepared to stand up in front of the world and say "this is great" he should have first been prepared to dig a little deeper into the true nature of the new app.
True enough, but my point is that there is a bigger problem: He ran an org in which nobody tackled him in the hallway and said "WTF This is a piece of crap! We can't release such a POS, and if you do I quit!"
An organization is not fixed by chopping only one head, there are no doubt lieutenants that need to be axed.
Do you know that they didn't? And there is a lot of gray area between tackling and release that a good manager should be able to dive into.
I know that they either didn't tell him, or didn't tell him in a manner that he listened.
It's really not rocket science: An organization is not fixed by chopping only one head.
People several levels down are getting big bucks too, they're necks are only incrementally less exposed. It's not like these are gov't jobs.
His primary job is not "building good Maps", it is "building an organization that delivers good Maps". Having failed products may be excusable for some reasons; having products fail because your team is not functioning is not excusable, having your team be like that is 100% direct execs fault and responsibility if he has been there for more than a few months.