Because it is our Right to complain about receiving what we ask for!
Yep. If we behaved this way in a restaurant, they'd throw us out.
"HEY, WHAT IS THIS SHIT?"
"Um, sir, that's the cheeseburger you ordered, exactly the way you ordered it, which was not an easy task."
"BUT CHEESEBURGERS ARE BAD FOR ME! WHY DIDN'T YOU BRING ME A SALAD?"
"Sir, please leave the restaurant."