Tallinar, do I trust
myself? Sure. The question is whether I trust
all the other people at a stadium... Perhaps I think human nature is more malleable and context-dependent than you do. Some men are very, very good, and remain so under all circumstances. Some men are very, very bad, and remain so under all circumstances. Most men are part good, part bad, and behave well or badly depending on the circumstances.
Football games (and other contact sports) are calculated to create an environment where spectators are induced to be "bad." After all, where else do tens of thousands cheer "hit him!" or even "KILL HIM!!!" where the object of their ire has done nothing to them, and is, in fact, nearly always a fellow American? We have as near to Roman blood sport as we want to come, we get gyrating dancing girls, we get fireworks, we get booze, etc. We all get to walk on the dark side just a little bit. And that's fine. It probably helps most of the people in the stadium to stay a little more gentle and sober and rational in the rest of their lives; let off a little steam for 3-4 hours on Saturday or Sunday, be a better person the rest of the week.
But for those 3-4 hours, many of the spectators are worse people than they usually are. They percieve every bad turn of events as the result of incompetence or conspiracy. They don't back down from altercations. They readily take offense from anyone wearing the wrong jersey. Even in this worse-than-usual state, the vast majority still won't cross the line to criminal behavior. But what if .005% will? That's an average of about 3 per NFL game (67,000 avg attendance). This jives, by the way, with the NFL's own average numbers of 3 arrests and 25 ejections per game.
Now imagine that 10% of the spectators are armed. That would mean that, on average, just under one out of three NFL football games every week would have an individual with a firearm who was also breaking the law in a flagrant enough way to get arrested. Given the catastrophic consequences of even one shooting in an NFL game, I think the risks are very, very high.
I've seen cops settle down a lot of unruly football fans. Without guns, the LEOs have a few seconds to get things under control before anybody gets hurt. With guns, the cops have no time at all. Out in the wide world, seconds aren't enough time for cops to respond, and so we have to fend for ourselves. In a football game, LE is much closer to hand and therefore much more effective and fast-responding.
All these factors give me great concern about having serious weapons in the stands at football games.
Edited to add: Just saw your more recent post. My argument is not in any way predicated on
you being destined to act like a buffoon. It's predicated on one out of several million of the attendees of football games anually acting like a buffoon. Unfortunately, I like those odds.