You are making an observation. I'm giving you the inference.

Sweet lookin' beast for sure.....not sure how well it would have sold in a 4 door dominated sales landscape.  

How resource intensive is it to engineer a platform that can accommodate both front and mid engine layouts? It's gonna be more expensive than engineering a normal car platform for sure, but do we know how much more expensive it is? 

Sedan sales were falling for decades as truck and utility sales increased.  That made it easy for mfrs to discontinue them in favor of more CAFE friendly models and/or to divert those resources to new BEVs.  It’s a combination of all those things.  Take one away and it might be different.

With modifications, sure.

I'm bowing out of the back and forth after this last comment, as it's clearly not going anywhere.     Nothing has been outlawed.  If buyers demanded a low, sedan-like silhouette, automakers would find a way to build it profitably within confines of CAFE to satisfy buyer tastes.   CAFE didn't make buyers dislike sedans.  Instead, buyers have accepted other forms/silhouettes, making it easier on automakers to skirt CAFE standards.  Meanwhile, models in all segments grow, and new models wind up slotting beneath those.  Examples - Escape, Bronco Sport.  Civic, Fit, etc. etc.

The Super Duty-based Bronco Concept begins at a little after 29:30. Many good cars here.

My sister had an Escape to drive her kids around and could have used a bigger car that she didn't get till about 4 years ago, when both kids where in their early teens when she did. They could afford to get a bigger car but used the Escape instead.    There is lots of factors of needs and wants when it comes to car and the biggest one is cost IMO. Next up is want, because some people will pay more to get what they want.    The other thing cluttering this up is the blurring of performance lineup-with the performance an EV can provide, is there really need to have an extra sporty model when low end model can hit 14 seconds in the 1/4 mile and has a sub 6 second 0-60? Those are pretty kickass numbers for a performance vehicle that has lots of flaws to it from 10-15 years ago. 

This cannot be improved.

You are reading but you are not comprehending. Car companies have found a way, this is why compact CUV is the 2nd biggest selling segment now.    The Focus and Civic buyers from the 2000s are still there. They are buying Bronco Sport and HR-V now. They are exactly the same size but Focus and Civic from the 2000s which have been effectively outlaws because CAFE.    Most buyers don't care if a car company submits a car for EPA certification under the car rule or truck rule... it doesn't really impact their buying decision. But that's the loophole that makes it possible to still offer small compact vehicles.   Take for example the current Chevy Trax. It is a very conventional C-segment hatchback with slightly raised suspension that is the same size as the last Chevy Cruze (in fact, this model replaced Cruze in China and Korea). It is impossible for GM to sell this vehicle  as a car in the US under CAFE but totally fine to sell it as a SUV because of the permissible truck CAFE footprint target.    These pairs of cars are the same size. The newer one is a "truck" according to EPA.   Chevy: both around 178" long and roughly the same footprint   Ford: both around 173" long and same footprint   Honda: both around 176" and same footprint