Pissed or not is not the direct issue. Violence is. I certainly wouldn't be breathalising on the turnstile, wind up or not. You can have all sorts of pissheads: merry, jokey, sleepy. Like the dwarves really. As long as they are a well behaved pisshead and they are there for a good time, are respectful around children and families (maybe sit in the appropriate area of the ground) and don't intend on driving home, fair enough. Its a day out after all and we are all there for a good time. Its when violence occurs, that's the issue.
Some tossers will be drunk, some won't. You can be drunk without being a tosser but unfortunately you don't need to be pissed to give it the big one. Indeed looking at some of these reports of what happened, many weren't actually old enough to drink anyways.