I couldn't care less about sport. So I don't see Nadal's achievements as any more impressive than a wheelchair-rider's. The problem is, you are up against people who do. Sports fans. They can't explain it or defend it, but to them there's something fundamentally "better" about Federer as compared to a legless person with a racket strapped to his wrist. 

Sportists defend the male-female segregation of sport as necessary for fairness, and lament doping for the same reason. They are preoccupied with "purity" at a very deep, psychological level. 

It's all very stupid, and regressive, and patriarchal. It's all very Germany c. 1936. It's all very religious. 

So they don't care about wheelchair tennis champs, and neither do I. There is nobody who gives a damn. And so, there's no money or prestige in it. The bigger question is why we give any money in the first place to people who's only contribution is to smack balls around.