Why? Why not? I still haven't heard anyone say why it's in poor taste to criticise someone who's dying as opposed to someone who's already dead.
The reason is it makes you look bad.
People who cannot put their own issues aside for a short while to allow those who *do* care for a dying leader to come to grips with the situation, hurt their chances of having a *productive* discussion once things settle down. It is seen as an attack and hurts your own position.
Once you have riled someone up, they are less likely to be willing to have a rational discussion and the entire thread degenerates into name calling. Or, people who would have been willing to discuss the issues, and there are issues here, will just not post out of disgust at the lack of decorum shown. At that point the discussion dies because the only people posting are people who agree with you and it just turns into a gripe-fest. At least that is what I have seen, especially on the political threads.
My two cents...
Jeannie