The fewer people you have on the floor to set up the machines and other things you haven't automated yet, the greater the risk that one of them will mess something up and kill your profits. Each person on the floor has a much higher value to your profit picture than before you automated.
We can learn a few things from Mikhail Kalashnikov. His genius was to design a product—the AK-47—with intentionally loose tolerances that would still function and could be manufactured and maintained with the technology at hand. Instead of designing for precision, he designed for functionality.
There is a skilled labor shortage in our industry and there are two solutions to this problem: Hire skilled employees away from your competition or improve your own employees' skill sets. Each solution has advantages and disadvantages.