Gotta admit, the AK47 is a weapon that will get a person's attention. 7.62x.39 is a .30 caliber round that at close range inflicts major damage if hit in the torso.
The m4 (or newer version of the ol' M16) fires a 5.56 .22 caliber round that's extremely fast, and also extremely accurate compared to the AK.
I've been in combat in Iraq, and it was always nice being able to pick up an underfolder AK to carry along with my issued M4. The AK withstands sand, dirt, mud, etc., as M4 doesn't like that kind of environment at all. I'll note that on full auto, the AK is much harder to control than the M4. Even with a muzzle brake, the AK climbs up and to the right on full. It's better served to fire it in semi mode.
I can see why the towelheads use these vs. other weapons with tighter tolerances.