The fundamental problem with short courses is economic. You can't buy half a mower, so the cost to operate a nine hole course is always more than half that for an eighteen hole course. Therefore you have to charge more than half as much to play there if the numbers are to add up, and that tends to be resented by golfers.
Additionally, there are thousands and thousands of courses, overwhelmingly eighteen holes, whose development costs have long ago been amortised. It is well-known that developing a new golf course is economically marginal at best if you have to take on debt to do so. Combine the two factors, and it is easy to understand why, when people do push the button on building a new course, they don't _generally_ build shorter ones.
Which is not to say there isn't a market for 60-90 minute golf experiences, I think there absolutely is. But, if such an experience is to make a return on the investment needed to create it, literally everything -- location, property, design, operations, marketing -- has to be right on point. There is a reason that so many great courses were developed by super-rich guys for whom ROI wasn't their prime concern.