I am on Facebook for the same reason that most people I know are on it. To keep in touch with people that are not near home - family, friends, and so on. Why do people come on FR? They are both vehicles that can be used for good purposes. So, that’s my serious answer to your question.
I have family and friends all the way across the country from me and I don’t use Facebook to stay in touch with them. I use regular old emails. I can write messages to them and attach photos. If your computer is new enough, you can download Skype for free and view your pen pals on camera.
I don’t use Facebook and don’t see any reason too. Too many people are exposing themselves to too many problems and security breaches using Facebook. My advice: Don’t do what everyone else does. Do the opposite and correspond and stay in touch some other way besides “social networks”.
Facebook is designed to facilitate identity theft by providing family link info to the fraudsters so that they can spoof their way to control of your credit and bank accounts.
For example a common security question is “what is your mother’s maden name?” - A good ID thief can mine that from reading all of the messageas exchanged on your wall.
I know what you’re going through. I, too, have had real bad trouble with bullies and creeps on Facebook. Keep complaining to FB, get your friends and family to report the abuse and keep your fingers crossed. Also, post things to his page that contradict his hate. He’ll probably “unfriend” you, but what the heck.