@fresco,
OK then, let's talk about enjoyment of aggression. Again, I will use the boxing example (since I have personal experience with it and since you started this thread about sports).
My son is very athletic-- he has played (and played well) everything from baseball to soccer to rugby. But his passion is Boxing (and because of this, I have also developed an appreciation for the game).
Boxing is surprising strategic. He spends hours and hours in a Gym with a coach going over moves and strategies over and over again. When to attack, when to defend and how to respond to an opponents attack. A lot of what he learns is counter-intuitive, moving into a punch for example, and there is a surprising amount of precision-- the coach will spend hours correcting the fact that he returns his fist to one or two inches out of the place it should be.
But, of course, raw aggression is a big part of boxing. It is you against him-- a struggle that only one person can prevail. There is an immediacy, an urgency and an honesty-- knowing that this person will force you to do your best. This interaction is beautiful-- and is something that is part of every sport-- but comes to the forefront in boxing.
Surprisingly boxing is about control. If you get upset, or angry... you are going to lose your form a big disadvantage. Through a punch a bit too far, you are going to be hit by a controlled opponent.
Believe me, I am not a boxer. My son decided he wanted to box when he was 10 and nagged us until we got him lessons when he was 14. There is no question that he has not only enjoyed boxing.... but that it has been good for him.