IMO, the ‘brace’ thing was doomed from the start because it was a way to get something that acts like a shoulder stock to go on a short barrel ‘pistol’ making it a short barreled rifle without a stamp.
You purists out there can carp and whine all you want but I doubt any of you would use that ‘brace’ to brace a ‘pistol’ against your forearm instead of your shoulder, especially when many of the ‘braces’ can be extended to fit your shoulder. Flame away.
I think you're right, and do you remember a couple of years ago when the ATF came out with a ruling that if you shouldered a brace then you 'remanufactured' the braced pistol into an SBR and was in violation of the NFA? The ATF caught so much backlash over that that they withdrew the ruling.
The ATF knew they made a big mistake with their original SIG brace ruling, and have been trying to walk it back ever since, but the braced pistol market exploded on them to the point that I think it's too late to put that genie back into the bottle.
The pistol brace was a way to get around laws and regulations for 99% of those who purchased them, period. First, it was an SBR for folks who live in one of the 21 states where SBRs are banned, or just don't want the hassle of a tax stamp. Second, it allows cheating hunters to hunt with a rifle during pistol season in states that have such a season.
I 100% think short barreled rifles and suppressors should be unregulated, and I should be able to walk out of a store with either as long as I am not a restricted person. Unfortunately we have ridiculous regulation on both.
I don't think it's a matter of "purists", 'carping', 'whining', or 'flaming', unless we're supposed to believe gun owners are easy to categorize (or maybe that somebody has ESP and can tell why every AR pistol owner bought one).
I built a couple of AR pistols a few years back, just because I got the parts cheap, and I enjoy building firearms. Wanting an SBR never factored into it; I think short rifle barrels are a waste (which is why I ended up selling them to a local FFL a few years later, without even shooting them). I've met people who put braces on AR pistols just because they liked the look; apparently they thought the naked buffer tube was "ugly". And IIRC, someone posted here on FR that they purchased an AR pistol because it was legal to carry or have in their vehicle under their State's CCW laws/regs, but a rifle was not. There are obviously any number of reasons various people decided to acquire AR pistols, with or without braces.
Bottom line, a lot of folks are making assumptions, in some cases based solely on their own motivations, and applying those assumptions to others in completely arbitrary fashion. In particular, I've seen folks who jumped through all of the hoops and paid their $200 tax to get a 100% "bonafide" SBR (for whatever their own reasons were), who seem especially prone to that approach...
;>)