@Hyolobrika The caliber of that rifle is pretty ideal for deer. If you were hunting something larger you'd want a different rifle, maybe a 7mm or a 308 I'd guess.

Some states have laws restricting hunters from using semi-automatics (~20?). Some states ban all rifles and would require you to hunt with a shotgun, or at least in some counties (usually near larger populations because shotgun buckshot or slugs won't travel as far if aimed too high).

It's probably better to think of the AR15 as being a form factor that is ideal as it supports a lot of accessories. You could give it a wood stock and remove some of the accessory rails etc and it would be equally dangerous, but look less menacing to the average person.

There probably is a psychological aspect about the gun we should study though