Perhaps this issue with the dad could have been avoided if his daughter had simply sat down and discussed it with her parents before bringing the gun into their home. Perhaps there is a perfectly legit reason for her to have a gun when she's away from the house that she needs to convey to them.
But besides the fact the "advice" columnist gave some really stupid advice...the dad's hand wringing uninformed response and over the top description of the gun in question is kinda disturbing...and shows how little most people know about guns these days.
Dad sees a 'Glock 40" as a weapon of criminals. Dad needs an education. If daughter is pretty, or even if not particularly so, she can be a target for the types of folks who would use her like a rented mule and leave her in a shallow grave or a ditch somewhere. He needs to get a clue, here. Yes, it's his house, but if by kicking her out to live in an apartment she can barely afford, he puts her in a bad neighborhood, she'll be even more likely to need that weapon.
It's his house, his rules, but I think he needs to revisit his thinking on what rules he makes and why.