Because "trickle down" economy was somehow thought to be legit.
Like, the rich get loads of money, so they do big things to make jobs.

Except they don't.

Rich people hoarde wealth, and pay people to ensure they don't have to pay taxes.

Rich companies increase profits, which is about the sole metric of a successful company (and when a metric becomes a target, it fails to be a metric). Then they try to keep increasing profits by cutting costs.

Oh, and wealth hoarders then bet on companies ability to constantly increase profits.