I don't understand why folks are so worked up about this.
iOS has never had turn by turn navigation.
iOS6 has ADDED a major new feature, turn by turn navigation.
The maps are different and maybe not as good (I haven't had an issue with it). Why is this a big deal? You can still get google maps by going to "maps.google.com" in Safari.
So you get the best of all worlds. Turn by turn navigation and google maps if you just want a static map.
iOS6 has ADDED Siri navigation control. I think its simply awesome. I've successfully done things like,
"take me home": It knows where 'home' is and navigates me back.
"navigate to best buy": It has successfully looked up the business name and either given me a list of places to choose from, or immediately started navigating me there.
How is this not a HUGE improvement over what was available in iOS5?