Here's the thing. I know it's an old chessnut, but if you're a scrote who wants to own a firearm for the purposes of criminality, you're highly unlikely get a legal one, are you?
I'm not saying that firearm possession should be available to all. Of course there should be checks and balances.
But I'm really quite convinced that responsible firearm ownership is a Good Thing. You only need a very small percentage of ordinary people to be properly trained in how to safely and legally keep and use a firearm in the home before nobody other than the state knows where the guns are. Similarly, if the bad guys had no idea whether or not the person they were about to mug was an ordinary citizen with a concealed carry licence, it would make people think a lot harder before committing crimes against the person.
Not everyone wants to own or carry a weapon. Not everybody is fit to do so. Even if they are, it's a hell of a responsibility to carry a deadly weapon and to take the choice that in extremis, you'd be prepared to use it to take life in order to defend life. It's a judgment call on the part of the proper authorities to say who is unfit to be given a license and then a judgment call on the part of the individual as to whether or not they can bear the responsibility. But that's not to say that some people won't think that responsibility is worth the benefits for the individual and for society as a whole.
It's a bit like cycling. Sure, every so often, someone on a bike is going to get hit and maybe even killed by a car. That's horrible and it's seemingly quite avoidable. But is it reason enough to deny the massive good that can come of the population owning and using what are no more than sophisticated tools?