Embedding a map with a search field in an HTML page is no different than maps.google.com either, but you will be subject to the API terms because those are the terms Google has decided upon. They could ask browser vendors to pay too, if they wanted to, but have chosen not to. They chose to charge those who implement software using their API. A Maps app like Apple's, which does far more than pointing to maps.google.com, needs to use the API service, which Google has decided to charge a fee for. Granted, Apple could have struck an independent deal with Google to use the service without said fee. That, we will never know.

But what reason would Apple have to go out of their way to maintain their own datasource (and pay other vendors, like TomTom, for help) if Google's data already fit the bill? Even more so if Apple was going to be paid to use it as you speculate. A dislike for Android isn't reason enough, especially as this move strengthens Androids position for the time being. The only logical explanation is that Google wasn't willing to play ball, for one reason or another.