There is certainly lots of truth in this statement. Love and revenge are two of the key themes in this novel that result in its plot and the way in which Heathcliff sets out to seemingly take over and destroy the Linton family. What drives him is his love for Catherine, and this, even after her death, is something that impels him forward on his path to perdition as he seeks to revenge himself on those who he feels oppose him and opposed his union with her. This is why he gains revenge on Hindley for the way in which he treated him when he was master of Wuthering Heights, and also the way in which he gains revenge on Edgar through the way in which he marries his sister and then forces his beloved daughter into a marriage with his son and tries to keep her from being with him when she dies.
However, let us also remember that Catherine is a character who is consumed with revenge just as much as Heathcliff, in some ways. She in effect kills herself because she is so annoyed by the way in which both Heathcliff and Edgar stay away from her at her time of need. Revenge is shown not to be the exclusive property of Heathcliff.
In addition, the overarching theme, and in many ways the cause of the theme of revenge, is the love that Heathcliff and Catherine have for each other. Let us remember Catherine's famous description of her love for Heathcliff in Chapter Nine:
My love for Heathcliff resembles the eternal rocks beneath: a source of little visible delight, but necessary. Nelly, I AM Heathcliff! He's always, always in my mind: not as a pleasure, any more than I am always a pleasure to myself, but as my own being.
It is this love that is shown to endure throughout their lives, and even beyond, as the rumours of ghosts and spirits that walk the moors shows.