Undoubtedly Apple has many employees in its legal department who would have demanded that the attribution be added if they knew the full story.

But it is easy to imagine that no one in the team of people who carried out the technical work to get OSM data into the product told the legal department where they were getting it from, or took responsibility for making sure it got put in.

The overall result is indefensible, and Apple's senior management should have had processes in place to audit their products to make sure they comply with the legal requirements for all third-party code and data they use. However, not doing it is easily attributed to incompetence and not malice.