Do power wheels trivialize driving? Wrestling action figures trivialize wrestling? And if so, will you also deny your children those? After all, driving accidents kill tons of people annually, and wrestlers have a history of drug abuse in their profession.
Where's this logic end, and begin?
I think people are looking to criticize you because you first took the stance of berating the child in the situation. You then admitted to everyone that you aquesed to your wife's demand to bar your children from playing with toy guns, justifying it with typical liberal-esque appeals to the misuse of firearms, as if a firearm's only purpose is to take away life (It isn't. It's also to save/protect lives, property, and provide food; the last one, hunting, having to be pointed out to you as completely reasonable, even it today's world).