Well this is a fucking stupid argument. Where do criminals get their guns? From stores or private sellers. If more extensive background checks were implemented, where would their guns come from?
I think their should be some sort of system like registering a car. You go in every year or so and show them that you have all of your guns/that they're in proper working condition. This way, if a gun were to disappear from the system the owner would be flagged at the next registration date. Responsible gun owners don't just lose guns.