The Principle of the thing...

So about a month or two ago, we stopped carrying plastic bags. Call it our contribution to saving the environment. We always used paper bags by default unless the customer specifically asked for plastic anyway, so it really wasn't too bad of a transition. We had quite a few really irritated customers, and probably lost some I'm sure, but after two months, I think it's time to let it go.
The only plastic we now have in the store are A. the flower bouquet bags, and B. small, thin bags like the ones you wrap meat and produce in. They are for, you guessed it, wrapping meat and loose produce.
So I had this guy come through my lane today with three large Styrofoam cartons from the deli. He said to me, "Put this in that plastic bag", and pointed to my little roll of meat bags. "I don't like your new policy."
So I replied, "Okay, but it's not going to fit very well."
And the gentleman replied, "Well I don't really care. It's the principle of the thing."

The principle of what? Ruining the environment? putting hot deli cartons in a very thin plastic bag so the plastic can melt and fuse with the Styrofoam? So I abide by his weird command and of course, as soon as I wrap it it immediately falls over because, like I said, the meat bags are thin and virtually useless. I hope he had something like chicken and mashed potatoes in one of those, because I guarantee it got everywhere.
JUST TAKE A PAPER BAG! GEEZE!