>If an employee is doing an unpleasant, dead-end job with no prospect of advancement, they have to make a value judgment. If there's no prospect of advancement or any kind of wage growth (they're "low skill", so they'll be replaced if someone cheaper comes along), let alone security, then why stick around?

Exactly my point, and that's what they are doing.

There is no prospect of advancement possible. It's a small operation with 15 or so total employees. Under normal circumstances I would agree on a much larger scale.