Andre is a tennis legend. He was also married to Brooke Shields. Unfortunately, this makes him public property. Okay, at the very least, it makes him fodder for gossip mags. I like Andre and respect him as an athlete. But he is only a tennis player. If he were a Nobel prize-winning author or diplomat, well then I could expect the world to be a little more fascinated. But he is only a tennis player.
As for the rest of your list, with the possible exception of Sacha, none of them, or at least those I know, are doing anything to better the world, to increase awareness of issues dealing with poverty or disease. Fascinating they're not...
Sacha is a genius, albeit in the 'crazy as a loon' category. I think he has no shame and balls of steel to do the things he does. Personas aside, he is a very intelligent, well read man who isn't afraid to put himself on the line. I just wish people like him would use what they have to help the world rather than take the piss out it.