Ken Nice showed me the fresh hydroseeding at Old Macdonald (Hole 4 I think) and it was unbelievably tacky. Nothing was going to move that stuff. Consider me sold on the technology.
The UK isn't quite such a hot bed of hydroseeding expertise and though I know they did a fair bit at No.7, I looked into it when I was based in NE Scotland and it was considered by my clients to be prohibitively expensive. They preferred the 'perfection' of a mature turf surface. You'll get no argument from me over the long term benefits of seed over turf. I merely offer a possible explanation. Of course, it may be no more than a part of Donald's press visit. "Show them fresh, green turf."