UK isn't fairing badly on WGT me thinks...St Andy and Royal St George as full stroke courses plus Celtic Manor as CTTH. If WGT maintains its ties with the R&A there will be more full stroke UK courses coming up (this year would be Royal Lytham & St Annes).
I agree it would be great to see more "world" courses here, but (1) WGT's capacity is maxed at 2 HD courses per year, at least one of which is USGA, and (2) international courses are more costly and logistically challenging for WGT compared to US tracks. So unless there's capacity and third-party financial investment, don't raise your hopes too high...