[wisty]

Turning up to a potluck with no food says "I don't care".

Turning up to a potluck with a bag of garbage you got for free in the dumpster on the way says "I don't care, and I'm so dumb I think you're too dumb to know this is trash".

[handoflixue]

This is more like bringing fast food burgers. Yeah, it's a bit lazy, but some people do actually appreciate the effort. And post of the people complaining aren't even part of the potluck.

[imhoguy]

"I don't know. Do you want me to figure it out?" would be my take, depending on circumstances.