Marillionfan.. Really??? You don't see it??.. yet you explain it pretty well in your reasoning,.. Scenario; The police are searching an appartment or a car (for whatever reason), and find a gun.. IF the mere posession of a licence, as you point out, shows you have good intentions with the gun, that very fact will show whether the gun is owned by an upright citizen or by someone who intendes to use it in criminal behaviour.. Since owning a gun without a licence is a crime, the police needs no further evidence to take action against the one who will (by your logic) be demed to be a criminal. The gun will be taken from him, and most likely the offender will be arrested or fined... If there was no licence requirement, the police couldn't use the possession of a gun as any form of evidence for anything, and could find a huge arsenal of weapons of a type that only can be intended for crime, and have to leave it without any actions (as everyone are innocent, until commited a crime)
Like you said; Licenses are <usless filler words> for people being honest. Why are you americans so darned scared of taxes? You don't like having the services the gov provides? Do you believe that dimlomacy, homesecurity, police, firedepartment, diplomatic relations, etc, truly could be funded on a volounteer basis??? Those services are there to protect you and get the neccessary safety in the lives of US o' A citizens lives, and it HAS to cost money and it's you who are supposed to get the benefits from it so isn't it just right that you pay?..
Also when it comes to giving an extra "tax" for specific merchandise, f.ex. guns. Those extra fees are supposed to be a deterrent for people who aren't serious about how much they want to own the merchandise in question (also known as the people who will be careless with it).. and the people who couldn't really afford all included costs of owning one, like getting a safe place to keep a lethal weapon, or go to the shooting range to learn to safely handle one. To reduce usage often go hand in hand with reducing missusage.
This reminds me of a completely unrelated law that you can't bring a gun into Clark County, NV unless you get a license for it in the county seat of Las Vegas. If you can't bring it, how do you get the licence? Sometimes I think these laws are just made to make us squirm...