Facebook survives because of its efforts to improve the quality of relationships and interactivity among users. This is bound by a very fragile thread and can be easily damaged with stupid features like a “dislike button”. Here is what I think.
Facebook has been successful mainly because of its ability to connect people and suggest users to make relations possible, even with strangers.
What makes a social network really “the best” is the way it handles and promotes conversations, and hence establishing relationship among users.
What makes a dislike button really inappropriate? Well, let’s face it. Facebook doesn’t trust its users. The chances of a dislike button being misused are very high. Internet trolls, haters, accidental dislikes, pay-to-dislike-a-post, etceteras are only a handful of examples how the button can be abused. This will discourage conversations among users.
If you like something on a social network, you can choose to like/ up-vote it. If you don’t agree with something, you can simply write in a comment expressing your disagreement. If more people agree with your disagreement, they’re likely to put a like on your comment. This get’s a conversation going and opinions are shared. Conversations make a social network SOCIAL.
Introducing one sloppy feature like a dislike button can quickly destroy the integrity of Facebook. It would be asocial.