Craig’s life at home is shitty. Excuse the pun. 

IF Craig doesn’t go to school, learn a trade or find a job, he’ll be stuck at home — and the writers succeed at making being stuck at home a gross and unappealing prospect.

IF Craig doesn’t find a job (and rent money), he’ll be kicked out of the house and have nothing. 

This is a great example of using humor to communicate stakes.