As I have no idea why a person should not speak ill of the dead.
If you hate a person and then they died I can understand not speaking of em. Just why is it demanded you have to respect em. I guess I'm weird than the common thing to do as I would rather have who hate me continue to hate me well after I'm dead than give me useless respect they couldn't do when I'm alive.

Acknowledge the dead, but don't give them respect ONLY after they are dead...it makes you look rather shitty to folks who respected em while they were alive.