Sometimes, some people just delights in making other people's
lives hell, by saying bad things about them, and make things
difficult for them. When u experience joy, they ask "Why so
happy.", when you sad, they will delight and revel in ur
pain.
All I can say is, ignore them. After I post something, I would
seldom, if ever, reply to anyone or anything that I felt is
attacking me. No point making them happy.