SpongeBob claims that "Squidward's always been there for us when it was convenient for him!" Really? Like when? I know there was "Christmas Who" but only Squidward and Santa knew that Squidward did that good deed.
I think after getting different answers from Evelyn and Larry, Spongebob decided to change his approach by having everyone pretend that Squidward was the fireman/guy in the ambulance/someone of importance in their lives so they can find the motivation to help him.