40-hour work-week as a tool of emiserating economic growth

“But the 8-hour workday is too profitable for big business, not because of the amount of work people get done in eight hours (the average office worker gets less than three hours of actual work done in 8 hours) but because it makes for such a purchase-happy public. Keeping free time scarce means people pay a lot more for convenience, gratification, and any other relief they can buy. It keeps them watching television, and its commercials. It keeps them unambitious outside of work.”

It sounds like it makes sense in retrospect but this seems like it requires to much premeditated coordination among practically all industries, making it very unlikely. If this were the true motivation, we’d see certain industries that do not rely on consumerism dismissing the 8-hour work day to maximize productivity.

Why would an industry that doesn’t rely on consumers seeking consumerist satisfaction try collude with another industry? It’s not like they all get together to make these kinds of decisions.