The sad but real reason a ton of this is happening is one very big word that is typically not present in things like car / airplane design: flexibility... flexibility to change the user controls, flexibility to fix problems, flexibility to let the SW team work up until the last minute to get stuff working, and the second part that goes with this is cost. Touchscreens mean increased flexibility for the design and better control over cost to deliver features. Unfortunately, if the display dies and you can't see anything, then the car or plane may crash... so sadly it will probably take a couple of those events happening for this to be changed to have some kind of redundant systems that the pilot can use when the display dies suddenly.
If something needs that much flexibility in it's UI that people are messing with it at the last minute it doesn't belong as something people should be messing with while driving. The OP talks about HVAC controls. How much flexibility do you really need for that? The interface has been standardized for a long time. It's a known quantity both from a design perspective and user perspective. Ditto for common audio controls like volume, pause/play, skip.
You'll often see screens surrounded on all sides by physical buttons. The screen can be updated and changed over time but the interaction is still physical.
There already are redundant systems like the ones you want. Multiple displays. Most planes that are heavily reliant on screens for instruments/navigation, touchscreens or not, have two of them at least. If one fails, there is a button you press which condenses the information previously shown distributed over both screens on each individual screen (so, the remaining one if one has failed).
