In most of my experience, the site was chosen by the owner, most likely because they already owned it.
At Quarry of Giant's Ridge and Tangleridge in TX, I was consulted about site selection. Both times, they didn't follow my direction.
At GR, the choices included a few miles of lake front, but after the environmental permitting phase they opted to use the old quarry for optics. They did ask what kind of golf course I could put in there and were skeptical when I told them it could be great.
For the city of Grand Prairie, they also had a lake front site, but it would have been leased land, and to them, going to a parcel they had bought for a park and owned outright was a bigger factor than a waterfront course.
I am sure there are others among my courses that I am forgetting off hand and I do have client in Europe right now who asked my input before finalizing his deal (also ocean front).
I guess the short version is, existing property, cost to acquire, cost to permit, or extend utilities and many other factors beyond suitability go into it. I even think Ross or Mac wrote in one of their books that a course could be built nearly anywhere, but the site factors (including having enough irrigation water) have to be in place. Still true today.