It should be hanged, actually, when referring to capital punishment, except when drawing and quartering are involved. It's a quirk of the language; hung is correct in most circumstances.

Yes we know, that's what made the comment funny - now you've spoiled the joke.

You seem to be using the word funny in a sense with which I am not at all familiar. Again, consider the non-native user of English, and the likelihood of encountering him or her on a site like this. "Ironic" grammar policing without an irony indicator isn't at all funny.

Is now a good time to point out that "poor" would be more appropriate than "bad" and that it should be reworded not to use "with"?

Am I missing the joke?

People are hanged, portraits are hung.