Because they don't have the necessary koalafications. (Derived from: )
Bear claaaaaarrrrrwwwwwwss!!!
So nobody will see their bare (bear) bottom!
Big holes all over Australia!
They couldn't find three wise men and a virgin.
He knew better than to drink and derive.
Because you can't drink and derive
It takes three to five years before anyone will hire them.
He hires Santa's elves during the off-season.