I already told you. For some people the guaranteed risk of a 45 kilo 7-year-old trampling your kid is less desirable than the remote risk of a crippling knee injury. It seems perfectly understandable to me, and not in the least ironic.
Similarly, I can understand why some would prefer the risk of being surrounded by people with weapons if it meant they could have one of their own, to the other understandable preference for being unarmed but having a reduced chance of encountering a hostile actor (or actress) with a gun.
Personally, I would prefer my kid getting trampled than busting his knee and I have no desire to own a gun where I live. But I don't think it's 'funny', 'ironic' or stupid for people to prefer different risks. And you're right, I guess that does make me smug. But I would've kept it to myself if you hadn't felt the need to judge the AFL-preferring parents.