It could be argued that the use of space is inefficient when local parks and woodland is mobbed with walkers. Offering up golf courses for casual exercisers would be more inclusive of society.
My course has gone to 2 balls at 6 minute intervals. Tee times are fully utilised from 8 til 14.24. That is a lot of golfers, and is probably more individuals using the course than would be out exercising on it if it was closed to golf, and open to the public.
The other odd thing with those exercising, is from my observations of walking every day from my house. Car parks near parks and woods are mobbed, roads jammed with poorly parked cars, many also dangerously parked, sticking into the road, on blind bends etc, because the council have blocked off the areas where parking was safe. Any way, the foot paths near the parking is busy as, but walk a quarter mile or so from there, and the woods and fields are empty. Hardly any one there. So people drive somewhere to exercise, but then don't actually exercise at all. Bizarre.