But That's None Of My Business

You say tomato, I say tomaaahto. Surely though, wouldn’t more guns make the event more secure? I mean, the only person who can stop a bad guy with a gun is a good guy with a gun, right? And it’s not like bad guys with guns are going to follow the rules. Why not maximize the chances of safety by arming everyone? Surely the Vice President of all people deserves just security as elementary school kids, wouldn’t you agree?

He has security- the Secret Service. And it's the Secret Service that's insisting no one, other than them, is armed at the event. The NRA is being courteous by asking people to not bring weapons.

Oh, okay. So it's the big government people who get guns while the rest of the general populace is unarmed. Seems pretty anti-second amendment to me.

It seems to me that you are unfamiliar with the terms "Duty" and "Honor". You might want to look them up.
Since the Secret Service is requiring someone not bring their weapon to attend an event, it falls upon the Secret Service to also protect them as much as humanly possible without sacrificing their primary objective: Protect the Vice President.
And the Secret Service isn't stupid. They will not slaughter the people in attendance because that would put a target on the back, front, and between the eyes of every single one of their agents. Vengence would be certain and Justice paid.
The Second Amendment is there to ensure the People have the capability to resist a tyrannical government and to defend themselves from aggressors. If the Secret Service attacked a bunch of unarmed civilians it would be the beginning of the end of the Secret Service.

Upvoted. You are correct, sir.