Map problems
Folks complained about the 3D version being all screwed up, etc. and I mean yeah, those kinds of things suck, etc, but I've had a lot of problems where I expect maps to be able to tell me and it hasn't been working. In Manhattan there are *tons* of problems, in NJ, looking for a gas station, or something like it has been a huge pain. i.e. BP is a gas station, and a business. Looking for corporate headquarters told me it was a gas station, while the gas station was the headquarters.
It's simple, stupid, blatant issues like that of which there are tens of thousands at least, (look how long google has been at it and there are still mistakes), not to mention in NYC you no longer have the subway schedules, poor directions for walking versus driving, lack of efficiencies (telling you to drive up 3 miles to find someplace to turn around to come back almost 3 miles to the "correct side of the highway" so you can go the right way when you could've gone .1 mile south and done the same thing.)
I've been giving it a fair shot and driving on major roads has been fine, but it's going to all those places not on the main strip that tends to suck and when you sold however many *million* phones, you have that many users with a potentially crappy situation where maps is concerned. At the very least a huge embarrassment for Apple, at the worst lost mind share for the quality they hold dear resulting in lost customers or revenue streams from partners.
When you look at the immediate impact they have by rolling out a sub-standard maps application like they did there are very real business implications from reputation to valuation and that is why Williamson was let go, not just that "maps sucked too bad."