I was chairman of my local club for about 3 years as well as serving on a LTA county committee. As a county committee member I got to go to some national meetings at the former LTA headquarters at Queen's Club, and met many of the people running the LTA. I was very interested in trying to bring more players into the game, but eventually resigned from both posts because of the lack of progress, and at club level the widespread opposition to tennis development.
On one of my visits to Queen's Club I was able to talk to Patrice Hagelauer, who had recently been appointed as Performance Director at the LTA. He ventured the opinion that the main problem with tennis in the UK was the clubs: he pointed out that in France clubs were primarily sports clubs whereas in Britain they were largely social clubs. He was right - this is the crux of the problem with tennis in the UK. I recently an article on my blog about the problems of tennis development in Britain.
Nice article there and I agree with parts. But I am not sure if the lack of clubs is the reason behind us having only two top 100 players.
Sure, it's not possible to dominate a sport like the US or France does unless you have a very strong grassroots program, easy access to tennis etc. But at the same time, you can definitely have a top 100 player every two or three years with whatever we have (plenty of countries with much less achieve that)...
Welcome to the forum, by the way. Nice blog you have there - Galbraith enthusiast, eh? Not that I am to a great extent...