I think we all know my views on this, but I'm going to say it again anyway.
Something girls have a hard time understanding is a guy's sense of identity and manhood. When he's being challenged, he can't just walk away and lose face like that - maybe if he's alone, but not in front of his friends and everyone else watching him. There's nothing a guy would rather do than walk away, but when he does he feels like shit for it and beats himself up inside for weeks, months even maybe.
It's not simply a matter of walking away, if only it were that easy. Do you really think that we want to fight and possibly bust our knuckles, have our teeth knocked out, get KOed, whatever, than walk away? I do not spar ever without wearing a mouth guard or gloves.. I don't even hit the bags/pads without gloves because it hurts my knuckles too much..
It takes a bigger man to throw the first punch - this is why you often see guys trying to get one another to throw the first punch by openly saying have a go, or pushing them.
All very easy to say 'walk away' when you've never been in that situation before and especially when you don't understand fight dynamics.. when adrenalin is pumping, your body is telling you to fight or flight. Instinct is kicking in here, so posturing, clenching of the fists, increased heart rate and breathing, tunnel vision, etc. kick in and sentences generally get shorter and shorter until eventually one syllable words like eh, fuck, cunt, or grunting leading up to just before when the first strike is thrown.
A lot of people are out of the fight before they even know they're in it. The person who strikes first is usually the guy who wins - I've seen it happen before.. my mate who had 7 years experience in martial arts copped a pissy uppercut to the mouth right off the bat which split his lip open pouring blood out, required stitches to fix it.
It's only physical damage, it heals with time.. it's a lot less worse than the emotional and psychological damage that comes from walking away from a fight. Even if you take your beating, you can hold your head high and know that you're a man. The reality is that most guys don't know how to fight anyway and they will both go all out and gas within 30 seconds or so and just give up. They'll then walk away with respect for each other and probably won't have another confrontation again, they'll have respect for each other.
Girls, on the other hand.. they will go around bitching behind each other's back, backstabbing wherever possible and trying to make them social outcasts. It's quite amusing to watch some of you girls bitching amongst each other