So the fact the course was there first is irrelevant. In any case their balls were flying into some else's property.
The course could have either redesigned or they could have bought that property so no one would be harmed but they refused to do so until they were sued.
So the property owners were in the right, the course was in the wrong.
You could blame everyone involved really. City should have seen this coming when they approved the course. Developer should have seen this coming when they were building the homes and worked something out with the course. If the course owners knew ahead of time where home lots were going to end up, they should have designed differently. The home buyers should have known their yard was going to be a target.
Stupid human tricks