I agree on the flexibility part. Interesting thought. Although that doesn't necessarily mean it has to be a touch screen. There are many non-functional buttons in my car right now, which might be wired but just don't perform an action. The car manufacturer could make it more easy to reprogram these.

You can see it a bit as a Playstation controller (or whatever platform you like), it has multiple programmable buttons. A car could basically have the same. A touch screen is not required.