Why doesnt Roger Federer go out while he is on top?

He is still a marginally good player butI have read in the media that he is paying off others to lose against him. Instead of going through this effort why not just quit? Everybody knows that Nadal is ten times the player Roger is or ever was. So why not just end the pretense and have this old croaker retire to some European pasture where he can stud all the ladies or lads he pleases?