I think this is actually a smart decision. Thinking about it from a systems engineering perspective might help. I spent a few years writing software for NAVAIR. I worked specifically with systems that are on carriers, but I assume it is the same for NAVSEA and destroyers. A touchscreen might be thought of as a COTs component, but there's not many choices when you take into account the mil spec standards that must be met with regards to vibration and salt water. The touchscreens that are allowed to be used are not cheap and if the display breaks, it must all be replaced. The whole monitor itself is the smallest replaceable unit. Physical buttons on the other hand have very cheap versions that have been passing mil spec for the last half century. Stocking LED buttons and non touch screen displays would be the cheapest option.