Why are there some people so disrespectful to the dead?

Okay so I know you're thinking that this is probably about Michael Jackson again, well, it is but I just want to say that when there are famous people who die, people can be so disrespectful. I've gotten the same when Heath Ledger died. Now, that MJ is dead, I am astonished and very angry at all the mean and distasteful comments I've seen on the internet. Even my own friends! It's so rude! Esp. the child molestation bs! Shut up with that already! When will you people learn that he was never convicted of that? Sooo disrespectful!