In any team sport there are rules of engagement and clearly marked boundaries of which you are either in-bounds or you are not.
The rules are documented and understood by both parties before play begins, both parties are playing the same game by the same rules.
Not every breach is picked up but they are enforced when they are, and if it is bad enough, you are sidelined or banished.
Aside from the won/lose part, should we not engage in business with the same ideology.