Most potential customers then.

I don't understand.

Ford's introduced the 5-day work week (reduced from 6), and the "Five-Dollar Day" and reduced work days from 9 hours to 8.

No-one talked about horses.

The notion of a work week presumes the existence of work, which is enabled by a product for Ford to sell: cars. How they manage the company, and what benefits they confer to employees is a separate question.

I still don't understand what point you are trying to make, or how it relates to product development.

I'm saying you're mixing up the subject. We're talking about what people want in the context of product development, you are not. The work week has nothing to do with product.

Instead of faster horses, Ford's mass production process was the product. All those workplace changes were to expand the pie.