In the monkeys paw, the monkey paw always grants what a person asks for, so why do people still fear and hate it?

Even though the Monkey's paw allows its owner three
wishes, it was not meant to be a blessing.  A spell was place on the monkey's paw by a
holy man.  According to the sergeant major, he "wanted to show that fate rules people's
lives, and that those who interfered with it did so TO THEIR SORROW." (pg 2)  Fate is
the force or power that predestines events in your life. . The sergeant major even tells
the White's that the first man wished for death as his third wish.  Mr. White did not
ask for anything evil or mean.  He wanted 200 pounds.  He didn't even need the 200
pounds.  He says he already had everything he needed.  But the curiosity got to him, and
he made his wish.  He did receive his 200 pounds, but at the cost of his son's life. 
The company paid him 200 pounds to compensate for the death of his son in their
machinery.  When he wished that his son return from the dead, who knows what would have
shown up at his door.  Edgar Allen Poe keeps us guessing on that
one.