Marty, are you hanging around those dreadful dreary cemeteries late at night again?
I think many things cause the death throes of an old golf course including cramped space and not enough room to stay up with the modern expectations of B&I distance enhancements. But also, market factors can be a killer. Courses of not much esteem that sit in the way of "progress". Not all the old stuff was a design masterpiece. Some just have to go in order that the new road, housing tract, school, etc are inevitably competing in the same space.
I think in the future, the death of many a course will come from petered out resources, i.e., water. Then, even well regarded courses of good general design may have to go by the wayside.
That other rather unpleasantness (you know the stuff about the enjoyment or excitement over the the decayed or dying remanants of an old course, and debate on what to do with the old girl play with her or give her a facelift)... well that is why they have places for that scary lot to go, like GCA.com, to get their jollies off.
