People seriously wonder why men fight? or rather - why they are competitive at all?
Probably because for men to "get" somewhere in life, i.e. to end up being desirable enough to someone to want to be with him and have kids with him - the natural imperative for most people - they have to acquire a job, some money, some stability, nobody gives you any of it on a silver platter. You have to compete with other people for it. Traditionally men were up against other men in the world for that, who won't stop to consider if you're going to be "okay" while they are pursuing their own success, now they're up against men and women too in the world of work.
A non-competitive man might breeze through life on the bottom of the pile if he's satisfied with that, but how many people are gonna just give him what he wants? How many women want a dude who's homeless and has no job? How many people would respect him for that matter? How many people will employ him if he's not "playing the game"?
It amazes me how people (especially females) think competition is this strange thing men do purely out of insanity, that has no bearing whatsoever on anything. The entire natural world is built on competition between species and within species and within the sexes, but males especially are made to compete harder since they are the biologically expendable ones. Since they don't invest much in the way off carrying offspring in most life forms, instead males are "sorted" by competition with others. Not a very nice fate for the male of any species, but what are you gonna do. Females traditionally expected men to acquire resources and then share them with their female partners when they raise children. Females weren't expected to go out into the world and get good jobs to satisfy the husband's financial needs, were they. It was men who were - and still are for the most part - supposed and expected to do that. Even in today's world, women like a man with a job - they often want a man who earns equal to them at least, or else view a jobless or poor man as a burden. Not a criteria females are usually required by men to fulfil before getting a look-in.
So blame biology for the competitiveness and desire to acquire status and resources in males that can be found reflected in men's desire to compete, engage in sports, and assert their status through violence and ruthlessness sometimes. Because it's having those resources and that status that means that man has a better shot at raising offspring with a woman. Obviously not every guy understands the mechanism behind the power play, not everyone is necessarily playing that game consciously, but the wiring in the back of our minds is the way it is because fundamentally we know we get nothing by being noncompetitive in life. I'm not looking to have kids, but I know being generally noncompetitive does me no favors in bettering my life. There's also the psychological importance of having goals in life and the assertion of self, which are aspects of competitiveness.
If I had to comment personally on competitiveness (and aggression), I'd say controlled competition (i.e. sport) is a healthy outlet for men. There is nervous energy and frustration wired in there which if not turned to the business of good can be easily turned to the bad. "Young men with nothing to do" has been known as a problem for millennia. It's wired in there for most and having something to divert it toward a sense of achievement, discipline etc. is the best thing to do. Hell knows I know what it's like to be without that and for it to find outlets in criminal activity or general destructiveness (or self-destruction). And I don't think dosing people up with drugs is the answer either. Competition is fine, there's actually nothing wrong with it - though we currently live in a situation in which social attitudes toward competitiveness is one of horror toward the idea and one that despises masculinity, failing to recognize the positive and constructive traits of controlled competition and aggression when channeled properly.
