10-4; There are rare exceptions (Ted Kennedy), but by and large, it’s not good manners to speak ill of the dead.
I don’t know whether Diana was or was not anorexic, bulimic and/or narcissistic, but the taboo against speaking ill of the dead is what allows people like Diana or JFK, who did not lead exemplary lives, to be deified in death.
We live in a celebrity-centric PR world. Sometimes the unvarnished truth would be nice to hear. We shouldn’t make up or accept characterizations that are untrue, either in the person’s favor or against, when the simple truth will do.