I won a Madden tournament in the city I was living in a few years ago. I was respectful to everyone I defeated. This says less about competitive gaming and more about the people participating in said gaming.
That's the thing. Also, I don't think the guy making the video has ever really played many sports. Specifically, when he mentioned rugby he was waaay off point. Sure, things get heated in a scrum and there's yelling/punching, whatever but you're also getting your legs raked by cleats and your ears possibly boxed. What doesn't happen, however, is anything after the scrum breaks. Transport the behavior of these "e-athletes" to any REAL sport, especially at that age, and you'd have a lot of ejections, suspensions, and possible eye gouging.
The weird thing here isn't necessarily the behavior of the CoD players, but the fact that's it's ignored (almost encouraged) by the "league" and "officials".