The talk of accuracy in AR rifles is interesting. I just acquired my own "platform", a Sig MP400. It shoots like crap. 6-8" groups at 100 yds. And with one magazine, it doubled or tripled 4 times. The other 3 mags that I shot did not. It seems to have all the precision of construction that would would expect in a box spring mattress which is what it reminds me of when listening to all the springs and vibrations humming with each shot.
I think its popularity is a function of 1. the entertainment industry, 2. familiarity for all ex military and LEO, and 3. it appears "high tech, modern" whether it is or not.
A Sig should shoot better than that unless you are using crappy steel case ammo or ammo not suited to the barrel's twist rate.
As to the noise, that is typical of the AR-15/M-16 platform.
It's popular because it is fairly easy to shoot, normally fairly accurate out of the box and modular, so you can do all sorts of things to the gun or set up multiple uppers in different calibers and configurations.
Having said all of the above, the AR reminds much of the Glock, a very good tool, but very bland and boring, it's just a thing.
