Why Jimmy refused salesman job offer and insulted employers?

This is one of the lowest and most nonsensical Jimmy’s momments, those 2 guys were so enthusiastic. As a salesman, the most important thing is to have the ability to persuade potential customers, and if Jimmy were able to convince them, that's enough of a reason to hire him. These guys were so nice and it’s so sad when their smile started to fade.

Every business owner in the world would be more than happy to hire Jimmy aa salesman.

And what he does afterwards!? He gets 10x shittier job. What is the point of this?