I think it's interesting how Tim Cook has somewhat become that charismatic leader of Apple that Steve Jobs once was.
This whole fiasco has been a needless embarrassment to Apple, and I'm glad Tim is acknowledging that. In the process of making maps better, I hope Apple will also reevaluate the internal bureaucratic paths that pushed this technology out before it was ready.
So you can still use Google maps from the browser? I did not know this... why are so many people complaining then?
Not really a mistake, it takes a certain level confidence in your product (iPhone) to know it's strengths and current weaknesses (Apple Maps), and to offer your loyal customers a temporary/alternative fix while you work on improving and meeting "the incredibly high standard". It's not like people aren't already opting for alternatives, Apple isn't that oblivious. This letter is more reassuring than anything.