IMO - I wouldn't say they are over complicated to a fault. My definition there of 'fault' being too complicated for their own good. I just went to our states International Auto Expo and was blown away at the clean organization of the engines. Today's cars do more with less waste than ever before. Today's 4 cylinder was the 1970's V8 (well not really, but its getting there.)
The main fault I see with today's engines is that they are too complicated for OUR own good, meaning we as the common car owner can't pop the hood and replace our own spark plugs, drive train or whatever else.