Gun control is not about guns...
AK-47's, Saturday Night Specials, AR-15's, High Capacity Magazines, mail order bolt action Italian Carcano's ...
It's always going to be "something" until we are left with "nothing".
Every semi-auto with a hi cap magazine sucks if you're of the AG persuasion.
The AR is just their poster boy.
This in a nutshell. Not to go off in the conspiracy weeds, but it's always been fairly obvious the gun control push has been about stability of government rather than prevention of street crime. There is a long term monolopization of force away from individual people and non-government groups.
A look at when these initiatives started in the 1930s at a time the whole social contract with DC was being changed (social safety nets, Federal Code of Regulations, etc.) helps provide context. Given the calamity of the depression, not so distant memories of the civil war and realization of the capabilites of modern weapons/communication/tactics shown in WWI its not surprising to want more controls. As time passed, it has become the standard response to potential civil unrest throughout most of the world.
Proponents here don't care which particular gun is being banned. It's simply a case they understand past attempts to ban all guns don't have popular support with the US public. So villainize some specific horrible extra scary one and try to pick away.
It's not that individual people are insincere in their hopes or beliefs that crime or insane acts could be prevented. It's a solution people have been told will help and when faced with such choices it seems like a reasonable idea.
Handgun bans have been proposed with fair regularity to protect the public from crime but thankfully never got through the Feds as just too many people actually see their usefulness and fought the proposals. All kinds of other restrictions and bans are offered up by local, state, and federal lawmakers in every legislative session. There have been tons of well funded propoganda disparing the ills of just about every flavor of firearm - handguns, assault weapons, sniper rifles, silencers - you name it, someone has a "research paper" showing how the public is at risk from it. Therefore it makes sense a lot of folks may be supportive of restrictions.
A quick look at federal laws: NFA 34 was sold as all about gangsters, but the reality of the measure was taxing to the point of prohibition real weapons of war like cannons, explosives, mortars, large caliber anti-material rifles and concealable long guns (at the time there was debate about including handguns). GCA 68 bans foreign guns without the "sporting exemption" and swept up all non-NFA guns from prohibited classes of people sold as as response to assassinations and civil unrest. We got the Hughes Amendment in a very dubious trade which prevented any new machine guns from reaching civilian hands. The now-expired AWB 94 was an attempt to get rid of any "military featured" guns sold as a response to gangs, drugs, and militias. The fact it sunset is a modern political miracle probably due in no small part to 9/11 awakening people to the reality of self protection, but the gun control groups view it as a serious error which needs to not only be fixed but improved with more coverage.