FB "like" diseaser

I really find it weird when people likes a post in FB when that post is a sad or a bad one. For example, "I have a headache :( " and you would see people liking it. WTF? Do these people who clicks the like button hates the one who post it? Or they just dont think and dont care what the post was about, as long as they can click the "like" button? Grrr... retards..