Do you ever buy anything when it's on sale? How about shopping at Costco or Walmart? By your logic (I think) you feel that bargain shopping is dishonest.
So-called "kitchen table" firearms dealers were just exercising an ability to buy directly from manufacturers without paying middle-men. What's dishonest about that?
By "exercising an ability" I think you mean, "exploiting a loophole". Applying for a federal license to buy and sell guns when you have have absolutely no intention whatsoever to buy and sell guns (merely to obtain them for yourself at a discounted price) is dishonest.
Call up some manufacturer, tell them you're a retailer and you want to order some items at wholesale. That OK? Is that honest?
Never mind. You probably think it is. That'll teach me try try to argue morality with someone who doesn't have a clue. Hey don't worry -- if it's legal that means you can do it. Screw everyone else. Look out for #1.