Is It Rude To Return a Food Container Empty?

There's a raging debate here in The Shark studio:

Gaby says it's "rude" to return a borrowed food container without refilling it with something else. This "something else" can be anything from hard candies to an entirely different meal. Evidently this is a learned tradtion for her, but I literally JUST learned about it. Honestly, I don't want my Tupperware or Pyrex returned with anything in it.  I'm just happy if it's clean. Also, I feel like that's a ton of unnecessary pressure for the person returning the container. I'm no stranger to superstitions, my family has a ton... Too many. But, I don't understand this tradition.

Is this something you do? Why? School me.

xoxo

Deena