It's because they are scum.
You don't have to know someone to give a shit about them dying. I saw a video today that showed an innocent boy being shot by Pakistani soldiers. He didn't do anything wrong and the soldiers all stood around and watched him bleed to death while he was begging for help. If you feel NOTHING after things like this, you just aren't a human being. I don't know the guy, just saw him in the video, and it was incredibly heartbreaking. He died and none of those *******s did a damn thing about it....and this person did nothing to deserve it.
NO ONE has to like Amy or her music, nor do they have to give a shit about her being alive or dead, but if you want to make a dickheaded comment, keep it in your brain or say it somewhere else. It doesn't matter who it is, it isn't funny when someone dies. It may not do anything to you personally because it is someone you don't know or care about, but everyone has a family, everyone has friends, everyone has someone who loves them. You wouldn't want people to make fun of your friend or family member if they died so don't do it to someone else.