Probably load up on financing to expand. Expansion floundered and they had to unload unprofitable and profitable locations to cover the debt.

Why didn't he have the ability to foresee the idea was bad?

portnoy is not the op

Am also wondering if part of the problem might have been timing. Did have 5 locations during the pandemic?

... although, having said that, the financing thing that another commentor mentioned I've read is often a problem of over expansion.

> What did they do that was so bad that it cost him 3 locations?

Skilfully timed when growing and succeeding. Unlucky timing when failing.