Okay, we didn't forget those things. People still make the "How is Michel Jackson like an Xbox 360?" joke, and
Heath Ledger (at least get his name right?) actually died as a direct result of said drugs, so it's not likely we're going to forget about that any time soon.
People that have actual beefs with the departed have kept those beefs right on going -- I really don't see anything out of the ordinary apart from traditional respect for the dead, which stems from religious beliefs that
the dead have ongoing influence in our lives [gratuitous link!], but developed into a notion independent of religion and more to be a question of culture. Furthermore, it comes of the commonly held notion that one should not speak ill of others when they cannot defend themselves -- the dead are nothing if not defenseless.
If you want to make sweeping generalizations based on your personal experience, that's fine, but you'll most likely be mistaken.