In the sort of circumstances where the police can actually act as defense, sure! But the problem is they are - pretty much by definition - only there to clean up after something like an assault or robbery. Sure, a DUI stop is essentially a cop defending us all from a slow-motion assault by a drunk. But if I'm unloading a bunch of expensive gear from my truck and get approached by someone who thinks they'd like to relieve me of it on pain of injury or death, the police simply cannot be present to defend me against that sort of thing. That's on me.
We had to brandish a piece to run off a seriously altered guy who was pounding on our door at 2:00AM one morning. Called the cops right away, but then the guy wound up at our back sliding glass door and starting to try to beat down that door with a piece of pipe while shouting threats. The only thing that changed his mind was a good look at the muzzle of a gun. The police were almost 20 minutes in arriving. If that had been my wife home alone, the cops would not have felt, at all, like an adequate defense. That has nothing to do with my respect for them and the hard, thankless jobs they do. But they are only rarely our first defenders. There's a reason we call them "responders" in that context. Shit's already happened at that point.
You responded in a justifiable manner according to the Constitution and law. You're correct. The police can't be there 24/7. Nor are they obligated to provide 24/7 personal security for every law-abiding citizen. Hence, the 2A. Keep at it. Personally, I would NEVER look for a way to hold you accountable for your actions ... because you did everything right in that case.