Why did Voldemort die though he had Harry's blood?

[pippin_999]

No: HPFGUIDX 177349


Pippin:

Dumbledore says in King's Cross that Voldemort is wrong to think 
Harry's blood will strengthen him. He does not explain why, except
to say that Voldemort would never have dared to take Harry's
blood if he truly understood its power, but that if he did
understand its power he might not have been Voldemort
at all. 

Voldemort thought being able to touch Harry proved that
all of Lily's protection had been transferred to him  but
it seems he was wrong about that.

I think magic at this level is not mechanistic.  Phoenix
song is the same way -- it grants courage to some but fear
to others, depending on their pureness of heart. IMO, Harry's blood had 
no power to protect one who so completely denied the nature of its 
protection. 

Pippin
realizing that in the Potterverse pureness of heart is not
a constant quality, but a variable one. Harry's heart is not
always filled with love but when it is, it is pure.