"...this experiment owes its intellectual roots to the industrial organization of cereal baron W.K. Kellogg, who replaced the rotating eight-hour shift schedule at his plant in Michigan with six-hours periods, resulting in an explosion in hiring and lowered production costs."
In Sweden, this is a no-brainer. In the US, for salaried workers, it's an interesting possibility. For factory workers? They were probably only paid for 6 hours, given a 36 hour work week to avoid "full time" status so paying for benefits could be avoided, etc.
I wouldn't be so fast to praise US businesses for lowering hours in the work week - there was an explosion of this practice after the ACA passed, so employers could avoid paying for healthcare.