It's been popping up on the pictures lately:
Guys that hold their carbine kind of over their shoulder to fire a la paintball marker.
You don't want to be all geared up for milsim? I don't care.
They'res no recoil, so why would you fire from tucked in your shoulder, you may ask?
Well you paid good money for your AEG or GBBR, might as well not look like a ponce while shooting it.
Kinda rolled into the treating airsoft like it's paintball (which on its own I have no issues with)