Why No Football Superterstars!!!!!?

how come there arent any lebron james or kobe bryants or tiger woods or alex ovechkins or ronaldinos of the NFL. people that just dominate. i dont mean like the ladainian tomlinsons and stuff that are just known as football players i mean tiger woods is known everywhere for being the best golfer ever (maybe the best ever) and lebron james is like one of the best ever. there arent any MICHAEL JORDANS of the NFL WHY???????