A Springfield 1903 is a much deadlier weapon than any AR, but no one mentions that one.
The left picked the AR weapons because of their appearance.
Scary black rifle.
”Scarieness” is an easy sell for anyone inclined to emotional decision-making (most gun-control types), but I think the popularity, and sheer numbers of AR-type weapons in circulation is what really gets under the lefties’ skin.
That’s why the Ruger Mini-14 is still popular. It’s a gas-operated semi-auto chambered in 5.56, but it looks less “assaulty” to the general public.
https://ruger.com/products/mini14RanchRifle/specSheets/5802.html