"Really, golf courses are taxed much lower usually, as they go as green open spaces (similar to protected forest areas"
That does not seem allright. A forest has lot's of ecodiversity, but a low cut golf course?
But sure, it is still green and somewhat alive.
Yep, and I would not say they are "open spaces" if the owners yell at you for stepping on it.
Golf courses are often full of exclusively native foliage, often protected areas, and wetland areas. With much more ecodiversity support than neighboring businesses, residential areas, and even parks.