Why not? Just doesn’t seem very secure.
Freedom brings with it the opportunity to make mistakes. The alternative is worse.
One could say, and rightly so, that places where guns are very much prohibited are among the more dangerous places in the world, because the good guys are prevented from acting strongly in their own self defense, and the bad guys know it.
Maybe so, but that't none of anybody's business but the owner's.
Put another way, the “security” brought by disarmament is a mirage.
If you are really pro-Second Amendment, then you need to arm yourself. It won't take long for you to realize that the anti-gunners' synonym for "very secure" is "completely unusable and unavailable to the owner".
If the state of Kalifornia truly recognized the Second Amendment, then the man in the article would have been carrying a loaded firearm on his person; and his other guns would not only have been secured in his truck, but they would have been further secured by an armed guard. What could possibly be more secure? That is how we secure the President of the United States.