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.

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.