LOCH LOMOND, Scotland (Reuters) - Former British Open champion Tom Weiskopf has lambasted his compatriots who last week pulled out of the U.S. leg of 36-hole international qualifying for next week's Open at Royal Troon. A field of 120 was initially meant to be chasing the 15 spots on offer at Congressional Golf Club in Maryland, but 46 players withdrew over the weekend. A further seven failed to arrive for their Monday teeoffs.