This is a great, thought provoking series of articles.
I was excited by both the IDx and the Santa Cruz concepts. Although I very much liked the IDx, I never expected we would get it as it was designed. I figured they would slap that retro body, or something similar, on the Versa platform and call it good. Having owned a Versa Note, I think it would have still been a fun little car, especially with a manual transmission, but I know others would have been disappointed.
I know that because that's how I feel about the Santa Cruz. Looking at the comparison photos above, I think Hyundai has done a good job of capturing the basic look of the concept, but they failed to deliver the small size I was looking for. Doubtless that Hyundai's reworked version will sell in decent numbers, but it's not what I was hoping for and has not brought me into their showroom.
Given all the complexities you describe, it's a wonder we get any new cars at all...