It's about map quality, not the app.
I was in Berlin recently, and Apple maps was utterly wonderful. They sourced the map data from some group of Germans who are presumably good at that kind of thing, and had superb 3D views and everything. The Maps app could manipulate it in lots of interesting ways the old Google data based app could not.
On the other hand, I am now in Northern Cyprus, and the Apple Maps app is utterly useless, whereas Google Maps is very good. My feeling is that software guys at Apple got all excited about what they could get the software to do, but failed to understand that it was the maps themselves that mattered, or simply discovered that sourcing good maps was hard.
It could also be that they only tested it in Northern California, which is once again a place where I hear that it works well.
Sadly, though, in most places it remains a debacle. I suspect they will fix it at some point, but they will have done lord only knows how much reputational damage to themselves by the time they do. Meanwhile, my iPad is much less useful as a navigational device than it was a year ago.