Many a high school essay has been written on the subject of revenge in Hamlet. The boy spends the entire play waffling on the subject, and even at the end of the play it's questionable whether he avenged his dad at all.
Has much been written on Hamlet's revenge of his mother's death? She's poisoned, and he springs into action instantly, going so far as to kill the king right in front of everybody.
What's that say about his relationship to his parents? He is the good son. He does the right thing, as far as the revenge thing goes. He's just motivated to do it for his mom, but not his dad.
I"m just saying.