Binaural
Eats Squid
Come on, now. Nobody here is advocating for banning guns altogether. At most, people are advocating for bracketing military-style rifles with other categories of firearms banned or heavily restricted . You correctly state their involvement in crimes overall is proportional to their numbers, but they are disproportionately involved in the most high-volume massacres. While overall it seems mass shooters seem to choose their weapons according to what's available (often a handgun), the specific capabilities of assault-style weapons is a significant multiplier.The restrictions listed in the articles have everything to do with increased vetting processes reducing homicide rates, and nothing to with access to type of firearm. If you vet against criminals, if you vet against the mentally ill, and if you vet against people with restraining orders you will have an actual tangible impact on saving lives. But nobody actually seems interested in saving lives, you seem interested in banning guns and pretending it makes a difference.
There's nothing wrong with your other suggestions, so why not apply both approaches? The potential downside is low, these weapons were previously banned for 10 years in 1994 without a successful legal challenge, and there are plenty of alternative long rifles that a gun owner can buy instead with less high-volume shooting potential for hunting and home defence. I know this feels unfair to you to single out these weapons without an overall plan, but a lot of legislative movements start with small, achievable goals.
(An interesting side note: I wanted to use mortars and artillery as my example here, but it turns out those are legal so long as you don't try and export them and licence any explosive ammunition. You can even buy drive a civilian tank with a 120mm main gun and act out your GTA fantasies. Merica!)
You ask for goals of those questioning current US gun policies, so I will state them: to reduce the number and severity of mass shootings in the USA by changing currently ineffective policies. Lax gun control is bright line of difference to other wealthy societies (that and healthcare), so it's not that surprising to see people want to start there.