When you are talking about a system as important as the steering of a battleship, why aren’t there redundant controls? Why not have the touchscreens but have mechanical controls in place to override the touchscreens if the need arises? Airplanes that are much, much more weight sensitive than a battleship have numerous redundant systems.
The reason that is not done is that there are no more battleships!!
There is extensive redundancy in McCain's steering system. There is no single point of failure. The problem was lack of training. When the CO directed the watch to reconfigure the helm, neither the CO, nor the helmsman understood how the system works or how to configure it properly. There are written procedures at the helm on how to do it (EOSS and CSOSS) that watchstanders could have referred to, but they were likely intimidated by the CO to act quickly. The Strait of Malacca is no place for on-the-job training, or trying something for the first time.