Why Do People Like Bad Things?

Why do people hit "Like" for things on Facebook that aren't likable? If your dog dies and you post it on Facebook, people should not hit "Like". That's like saying you like that the dog died. Or if someone posts a news article about a bad traffic accident and someone hits "Like", that's like saying that they like that there was an accident. I don't get it. Only say you like it if you really like it.