Someone was telling me only a couple of days ago about a time when Google Maps guided her to a nonexistent building out in the middle of nowhere next to some farm field in Pennsylvania. That story and some of my own Google Maps Fail experiences wouldn't scare me off of Google Maps since the tool, although sometimes mistaken, is much better than what I used to navigate back in the 90s! Reminds me of Louis C.K. joking about people complaining about not being able to get on WiFi when they're magically sitting in a chair 30,000 feet up in the sky. Apple wanted to build a mapping tool, and they'd probably get complaints from folks on here no matter whether they started with an excellent data source or whether they broke from their tradition and took a gutsy move that might hurt the user experience for a while. :)
I will give you that. My iPhone 4 is actually still on iOS 5 because I've felt hesitant and wanted to hear more feedback before I downloaded the upgrade. But I can honestly say that Google Maps has failed me and others many times, so it'd be interesting to know if the "failure" rates of the two mapping solutions are closer than one might expect, and that people are just posting the Apple ones online because iOS 6 is under more scrutiny at the moment.