I wonder how this happens. If Apple has the capacity to detect grass strips between roads, how do they misplace an entire part of town (into the ocean, no less). Isn't there some sort of process in place to detect false positives?
Imagine you buy in the outline of landmasses from some other company. If you pay staff to 'correct' those errors, it will be mostly wasted effort, since those changes won't be sent back to the supplier and won't make it into the next version of the suppliers data.
Likewise, if you start merging your data and their data in a way which isn't 100% legally separable, you get into all kinds of trouble. Flagging up where your own street map is in conflict with the suppliers ocean map could could as 'deriving' your street map from their ocean map, meaning you no longer have all the rights to your street map.
What's really interesting for me is at the beginning on launch of Apple Maps, there was only the major road and the airport marked, now most of the roads are there.. overplayed on top of the body mass which is still wrong. Its almost as if , while updating their road mapping to be more accurate, they have never in the past 5 years or so updated the shape of the land masses themselves