Sports Illustrated's S.L. Price writes:
...the French Open produces too many clay-court geniuses who never produce anywhere else. But Wimbledon's champions are almost never flukes, and their title runs always provide the necessary bones for an otherwise endless season...
Mr. Price, let me introduce you to Goran Ivanisevic, Richard Krajicek, Michael Stich, and Patrick Cash -- formers champions of Wimbeldon and little else. You can win Wimbledon with a big serve and a big second serve -- no other skills required. In the French you need an all around game.
Price is also ignoring that for most Europeans, clay is the dominant surface. There's the French clay, Wimbledon's grass, and the hard courts of the US and Australian Open. Then there's the rest of the tournaments. The Americans prefer to play those tournaments on the hard surface, the the Europeans on clay.
In other words, these "French Open flukes" are producing elsewhere; Price just chooses to ignore them.