SpongeBob was already late for work in 'Hooky' and 'Have You Seen This Snail', even though in 'SpongeBob Meets the Strangler' he has a perfect punctuation record.
Not only can Gary play the drums, SpongeBob can too.
Squidward uses a microphone to convey the orders to SpongeBob, when usually he just says them through the window, which would also be much easier.