As far as love stories go, this one is pretty dark. But make no mistake this is a love story. One that shows the darkest parts of being in love with someone. The dark things that come from selfishness and an emotional intelligence that’s below average are what you will see here. There’s no romance between Heathcliff and Catherine, just raw love that started when they were children.
Heathcliff being an orphan probably attached himself to Catherine pretty quickly and Catherine being kind of a brat never really thought of the power that attachment had over him. She basically thought of Heathcliff as toy to be discarded at first but then I think she realized that she loved Heathcliff after marrying Linton but it was too late to do anything about it.
When Catherine left Wuthering Heights all Heathcliff saw was someone taking away the one thing he loved and loved him, and not having anyone to teach him how to deal with his emotions how else could he react other than inflicting the same kind of pain on them as was inflicted on him? And to keep inflicting it even after you’ve destroyed the person, because once you go down that road it’s hard to do anything else.