There very well can be a communications cascading effect as well. How many people complaining right now about iOS 6 Maps are doing so because their friends are. Just as it's cool to be the one with the new iPhone 5, it's also cool to be one of the one's that is late to the appointment because your Maps app told you to take a left instead of a right. You're one of the crowd, and you have something different.
Maybe they should have released Maps as a downloadable app. Maybe they should have waited another year. Maybe they should have... They didn't and outside of transit* there is nothing that is absolutely terrible about the app. It's immature, sure, but it's not the worst thing to happen to the international community since the invention of the atomic weapon.
* If you know any objective-c and are complaining about the lack of transit options, contact your local public transportation authority and develop an app on your own.
How much of this is the self-selected sample of those who are irritated enough to complain? Data is not he plural of anecdote.