I think it's because it's easier to divide and conquer with 'big scary assault rifles meant for the battlefield' - it helps gather some people who are in the middle, and agree with Heller in that people should be able to defend themselves especially at home... if you say assault rifle bad - no one needs one to hunt with - you get some people nodding...
so it's easier to pass and claim a victory lap.
I saw a definition recently that said assault rifle bans.. any rifle with at least one 'military type accessory' - that wording is part of the charade. I'm guessing a forward grip, maybe a red dot would be in that?
Frankly if the grandma next door needs to use a weapon, I would hope that she is not limited by regulations such as that - I would like her to have as good of a grip and sighting options as absolutely possible. I'd rather her have an easily controllable SBR type of weapon, expandable stock and maybe 30 rounds of 22 winmag - this would be much safer for her and for the neighbors I think if something went down... JB's double barrell shotgun suggestion would not be the best protection for many grandmas, imho.
so maybe 'because of the popularity of hand guns' is that in a way, in that people in the middle want them.. I think some people will read that as in 'the popularity' is causing lots of shootings and that makes gun control popular.
maybe. all situations are different not an exhaustive suggestion(s) thought processes atm. ymmv.