Why is Hamlet so furious at Laertes for his manner of mourning his sister in Act V, scene 2?

In Act V scene 2 Hamlet's fury has ameliorated significantly. This scene is the final scene where the two meet and Hamlet attempts reconciliation with Laertes. He asks for his forgiveness "That I have shot my arrow o'er the house/And hurt my brother." Laertes accepts his apology in "nature" but apparently still is the one who is furious, not Hamlet. He says,

"I am satisfied in nature,
Whose motive in this case should stir me most
To my revenge. But in my terms of honour
I stand aloof, and will no reconcilement..."

This quote suggests that Laertes has not yet felt vindicated for what Hamlet has done to his father ,Polonius, and his sister, Ophelia. At this point, Hamlet has already decided that "there is a divinity that shapes our ends, rough hew them as we will", so he has relinquished much of his fury into the hands of God. He knows he could die and tells Horatio that "the readiness is all" as he willingly goes into a battle that he knows full well could be his end.