To add to my point...
The whole point of professional sports (aside from the entertainment aspect) is that people compete in order to determine a winner. Baseball, football, basketball, tennis, golf, hockey, soccer, polo, track, racing... whatever... the whole point of taking part in a sport is to compete to win. If cheating becomes part of the equation–if one side competes under different circumstances than the other side–we can no longer accurately determine who legitimately won, so the whole point of the contest is lost.