Is it a US thing that once you have the money you hang on like crazy.

You could argue is that the USA exists mainly because of an attempt to hold on to what were seen then then as very lucrative colonial properties. The citizens of the USA do not have a monopoly on hanging on to what they hold.

But in this case whatever the policies, those who were powered to enforce did not seem aware or if they did, they saw no reasons to follow them.

Perhaps there is at least some agreement that this is an area which needs to be improved?