I don't doubt that a lot of "scientists" don't do much of use - all I say is that professional athletes in my opinion definitely don't do anything of use, whereas at least some scientist certainly do. And if somebody cures cancer, let them be selfish as much as they want, they still gave something to society.
Nobody asks to admire pharma execs, but the notion that professional athletes should be admired exists.
As for inspiring people to take up a recreational sport: really? Is that what the Olympics do? It seems very unlikely to me, because the athletes are so obviously beyond the things normal humans can achieve. And if that is the goal, it could probably be had cheaper with some advertisements. Think not only the costs for all the branding, licensing and whatnot, but also the hours people waste in front of the TV.