My take on the topic is that those people who are anti-gun, most commonly politicians, celebrities, and others do not understand exactly how firearms operate. They are uneducated and have no clue when it comes to firearms-- so they fear it and shun it instead, and want others not to have access to them unless you are Military/LE.
Just look at Feinstein, Brady, and Piers Morgan. They all think all AR/AK's are fully automatic and will "continue to fire as long as you hold the trigger". They do not know, or care to be educated that civilian AR/AK's are semi-auto, and those full-auto/select fire are highly regulated by the ATF and mostly not owned by the general public.
They defend hunting when it comes to shotguns/bolt rifles, and self-defense when it comes to revolvers and low capacity firearms, but are highly against high capacity magazines and "evil features" when those are not the real cause of violence in society.
In short, ignorance and fear is the underlying cause.