Because he never pays his debts.
or
1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
or
The owner got tired of the (w)hole business!
or
Shamboo!
Frankenstein: Witch can you make me a lemonade?
Witch: Poof you are a lemonade!
or
You're the only bright spot in my life.
or