If there is one scenario I'm quite happy for a male (not to mention adult, and well-built) protagonist to take the lead in, it's a post-apocalytic world where everyone is trying to kill you. It's fucking ridiculous to expect that in a setting that is deliberately focussed towards violence, men should take the back seat just because it'd be nice to have a female protagonist. Modern society = rarely challenges physical strength, aimed more at intellect and social skills = equal opportunity. Primitive setting = challenges physical prowess = men generally better suited.
That addresses why the male character is the predominant action character, but not why he is the player character. The reason for the second part is, I suspect, it's more fun to be the gun-toting adult and have a neat little side-kick system than be the escort who isn't the centre of the action and have to try to control the main powerhouse through some sort of commands system as your main form of attack/defence. Remember Enslaved: Odyssey to the West? Probably had the same idea there.
Aaaand the E3 quote seals it, this guy's up in the clouds (wolf whistles for fuck's sake, it was mainly awkward laughter at best, same with the rest of that horribly scripted sequence).