I agree mostly with you. There is way too much use of electronics in a car to do something just "because we can." Just because they CAN use iDrive technology to tune the radio doesn't mean they SHOULD. The latest tire pressure monitoring systems require a $300 reset tool when you rotate or change a tire!!!!
Mercedes even admitted to too many electronic frills last year and is reducing the amount of frilly automation, when is BMW going to pay attention?
I do disagree regarding performance and fuel economy. The use of an ECU has just about doubled fuel economy and performance. Engine management is doing things today that could never be done just mechanically. I just read in AutoWeek that the new 505 hp Z06 'vette will get 18/25 mpg. For a 505 hp engine, that's amazing. I remember when a 505 hp engine could only get 10 mpg or less.
One new and interesting technology relies heavily on an ECU. HCCI - Homogeneous Charge Compression Ignition. This is essentially a technology that uses gasoline, methane, etc. in a DIESEL mode of operation - no spark plugs. It requires direct injection and very complex timing and cylinder pressure measurement to control it successfully. It provides a homogeneous fuel/air charge in the cylinder that burns at a lower temperature and more efficiently. Lower combustion temperature reduces pollution and actually creates more power and better gas mileage.
http://www.greencarcongress.com/2004/05/keep_an_eye_on_.html