Because capitalism incentivizes maximizing capital flow to the owner of the organization. Making labor interchangeable and delivering a minimally viable end product are both ways of minimizing capital that could otherwise be made to flow to the owner of the organization.

If you want to create a management style that optimizes for quality of product or optimizes for management styles that reflect the needs of labor, instead of a process that optimizes for minimizing labor, then you need to change the incentivization plan accordingly.