It says right there in the opening to that ancient thread that airsoft guns are to be considered firearms under the criminal code. The only change is that we now know that airsoft guns are in fact firearms under the criminal code.
Anyone who has treated them in a reckless manner is an idiot (lots of those around), lazy (didn't read, didn't ask), or a criminal (who cares).
I'll let someone else take over the minors thing. As for pellet and paintball guns, their use is prohibited just about everywhere except where explicitly allowed and the boonies, so I still fail to see where this will cause more than a mild inconvenience to anyone but idiots, the lazy, and criminals.