Why are they not a good idea?
Touch screen in particular are a bad idea as they require you look at them. However, decked out entertainment systems only serve to distract the driver from the task at hand.
You don't like advanced safety features?
LOL! NONE of those rely on something as finicky as DDR memory.
Navigation system that actually function?
Those aren't part of what make the car operate but rather an add-on. I have an old Garmin GPS device with updated map data in my car and it works fine.
Also this is largely irrelevant now. Modern safety standards all but mandate we computers in cars.
That's fine, I have no problem with ECUs. The problem I have is these idiotic and distracting entertainment systems. Conflating the two does not help your argument.