Explaining "Never speak ill of the dead"

What does it mean?

The phrase "Never speak ill of the dead" suggests that one should refrain from criticizing people who have passed away out of respect for them and their families, and because the deceased cannot defend themselves.

Tone

Origin

The sentiment can be traced back to the Latin phrase "De mortuis nil nisi bonum", which means "Of the dead, [say] nothing but good". It is often attributed to Chilon of Sparta, one of the Seven Sages of Greece.