How we cite our quotes:
"I seek no revenge on you," replied Heathcliff, less vehemently. "That's not the plan. The tyrant grinds down his slaves and they don't turn against him; they crush those beneath them." (11.51)
Though Catherine perhaps deserves punishment for turning against him, Heathcliff would do no such thing. What's notable here is that Heathcliff recognizes a pecking order: people pick on those beneath them.
"Oh, damnation! I will have it back; and I'll have his gold too; and then his blood; and hell shall have his soul! It will be ten times blacker with that guest than ever it was before!" (13.63)
Hindley loses everything to Heathcliff but must partly blame his own weaknesses and indulgence. He aspires to rob Heathcliff of everything and, like a devil figure, even wants his soul.
He had the hypocrisy to represent a mourner: and previous to following with Hareton, he lifted the unfortunate child on to the table and muttered, with peculiar gusto, "Now, my bonny lad, you are mine! And we'll see if one tree won't grow as crooked as another, with the same wind to twist it!" (17.119)
With Hindley dead, Hareton is left to suffer under Heathcliff. Like others who fall victim to Heathcliff's abuse, Hareton is a proxy for his father. That Hareton breaks the cycle is a reflection of his love for Catherine and his own strength of character.