First off, that sounds like baseless speculation. Second, there might be a causal relation between lacking motivation/interests and being jobless. It's not a representative sample of the population at large.

Jobless people are often stressed.

Jobless people aren't often just jobless. They're stay-at-home moms. They're people on disability. They're people with medical or mental conditions. They're people stuck in welfare trap - they get just enough money to make it not profitable to work (they'd lose it if they went to work, but no entry-level job will pay them more than the amount they get from welfare), but not enough to support any creative hobby. Or they have jobs - on the grey/black market, so that they can get both benefits and some shit untaxed pay.