Do you really believe what you posted?
You must know that the "loophole" example you referred to is not to the sale itself but the ability to avoid the background check at a gun show that would be mandatory if the sale had been made at a licensed gun shop.
As a gun owner/purchaser/seller in MA, I can assure you that this particular "loophole" is not necessary or even burdensome. All gun sales in MA, public or private, must include a background check. This is easy in the shops and shows where I have purchased firearms and only takes about 5 minutes. It does take a little more effort in the case of private person to person sales.
If this "loophole" exists in your state, as it does in the federal law, I suspect that, like most others that you can think of, it was designed into the law so the the politicians could have it both ways in their re-election speeches. When speaking to gun control advocates, they can say "Look at the gun control law I passed that makes background checks mandatory" while at the anti-gun control rally they can say "I preserved your right to buy and sell firearms unencumbered (at gun shows, nod, nod, wink, wink)."
The intent of the "mandatory background check" law is to try to insure that the wrong people don't get the guns, so the gun show exemption from the background check is a "loophole" in the "spirit of the law", whether by design or by lack of imagination (or incompetence) by the drafter of the legislation.
The same thing applies to all of the "loophole" examples Shafer uses; They're all designed into the law so that the politicians making the law can show people how to thwart the spirit of the statue while adhering to the letter.