As a Briton, I can confirm that there definitely is a significant portion of Britons that do tend to binge drink to the point of becoming violent. However, whilst significant, it's still a small portion - most Britons do not, and generally if you go into a pub, even late on a Friday or Saturday, it's full of drunk but friendly and good-natured people just relaxing and enjoying themselves.
I think, in my experience, what I've seen definitely seems to support the cultural argument. One point my friends have raised is that at Football (Soccer) matches, alcohol is generally banned because of how rowdy people get, whilst at Rugby matches beer is freely served and yet it remains good-natured.