Mind you, *before* Clinton was elected, most of these thousands of FFL holders only occasionally sold a gun to a friend or relative, or at a gun show. Most of what they bought went into their private collections. After Waco, though, the interest in guns jumped off the scale. "Kitchen table" gun dealers found that they could sell SKS carbines cheaper than the average rimfire.
The flood of those rifles (in various configurations as BATF changed the regs re: bayonets, etc.), together with other affordable, effective rifles (e.g., the various AK configurations) was giving the Clinton administration serious heartburn. One crackpot even emptied the magazine of one such rifle at the White House, remember? BATF reacted to the threat by trying to limit the number of people who could sell guns. Their first maneuver was to raise the licence renewal fee, then when that didn't reduce the number of licensees as they'd hoped, they came up with the regulations requiring "storefront" business locations. The average hobbyist FFL holder was, at that point, pretty much out of luck.
BATFE had made it more difficult and expensive to be a licensed gun dealer, but it's certainly not impossible. Also, not all of the FFL holders that BATFE chased away during the '90s quit selling guns at gun shows - many bought guns themselves and conducted legal private sales. They sold fewer and made less money, but they did it anyway, just to poke BATFE in the eye.
You can bet that eventually, the government will close the loop on private sales. That's what all of this has been leading up to.
At some point, the measure of success of the regulations becomes how well they prevent anyone from getting a license. Historically, it's the means by which the beltway bureaucrats assume control of things that are not supposed to be within the reach of the federal government.
I guess that's when I'm just going to stop caring about every gun laws. 10 year prison sale for private sales? Fine, we can make machineguns.