Google maps is possibly my favorite app that currently ships with iOS. I think I might give up email and texting on the device before I'd give up maps. I'm disappointed that Google maps isn't shipping with iOS 6.
The terms of the license agreement with Google for maps data likely didn't include the ability to perform turn-by-turn navigation. Another reason why they moved to their own maps backend for iOS 6.
I questioned why it was neutered the way it is now - not why it was created. I buy Apple products for wholesome user experience and the Google maps ain't one of them (neither is the mail app and so on). If you think this is a silly sentiment, then you must be pretty dumb about user experience issues in mobile situations.
Driving is not the only mode of transport. And SatNav is not the only type of useful map.
Paper maps are useful - an equivalent to a paper map that holds data for the entire world, can put a pin in my exact global location, and can tell me where the nearest Starbucks is? Yeah, I can't see any use for that at all.
Really now? As another anecdotal point, I freaking love it, and I'm saying this as a an almost-Apple-fanboy. I'm a pedestrian living in an Eastern European city of 2-million people, and I've used the maps app countless times.
Not that I wouldn't know my city (I've actually implemented 2 or 3 or map-related projects focused on the city I live in, just as a hobby), but because it is impossible to remember how exactly to locate the street bearing the name of an obscure 19-century music composer that just happens to be the address of a restaurant you're interested in. Or how when I got lost in the center of Athens, as a tourist, around Omonia Square ("I don't need a paper map, I can manage" I was saying to myself as I was leaving my hotel room), I heavily relied on the said map and on the kindness on strangers who had shared their home wifi networks to make my way around to Exarcheia.