As a point of comparison, food dishes that came about under similar melting pot circumstances are called "local" food while dishes that have ethnic Hawaiian origins are called "Hawaiian" food.
Hawaiian is an ethnicity. Hawaiian is used in specific contexts in Hawaii and using it to describe a specific type of shirt is not one of them. It has nothing to do with ideology and everything to do with accuracy and respect for a group of people.
I was born and raised in Hawaii. Not trying to come off rude but I don't need a Wikipedia article to tell me what something I grew up with actually is.
Hawaiian shirt is a crude marketing term that's only used outside of the original audience of the item.
When I tell people that only lawyers wear suits in Hawaii they don't believe me. Don't know if still going on but the legislature was pushing the courts to discourage the use of suits as well.
On top of all your reasons, it's just too hot and humid year round in Hawaii to wear a suit regularly. Must be pure misery for the people who have to.
As someone who was born, raised, and lived a significant portion of my life in Hawaii, I really wish he approached this in a better way or just chose a different place. There is still a lot of negative sentiment (arguably justifiable given history) towards "outsiders" within the islands and maneuvers like this do not help things. I don't see how the negative publicity surrounding this is worth having property and "joining a community" that you'll probably only spend Christmas in.