You are correct. But imagine this scenario at a track and field race: One runner, while jumping a hurdle, puposely knocks the hurdle over in the adjacent lane hoping to trip up a competitor, or at least slow him/her down. There is a rule against such a strategy, and the penalty is disqualification from the race.
Not playing by the rules is a form of cheating. In some sports it's considered necessary strategy in order to win. In every other aspect of life, not playing by the rules is looked at as underhanded or dirty. But in some sports, the importance of winning overrides personal integrity.
In pool, you can't just roll the cb up against a ball and call it a safety. It's a foul because the rules say a ball must contact a rail after the cb hits the ob. The penalty for breaking the rule is ball in hand for your opponent. Continued disregarded for the rules leads to automatic loss of game or match.
Don't get me wrong....I'm not a big advocate of rules and conformity. But not all sports have accepted or adopted the strategy of intentionally breaking the rules of play in order to win. Should they? I don't know....it'd be interesting to watch hurdle races where the runners could use any means neccessary (short of physical violence) to ensure victory.