+1Hyundai's V8 is not little, nor light, nor particularly responsive. It would absolutely murder weight distribution. The cost of the car would be nuts. And it would be one of the dumbest marketing investments of all time.
Ford Mustang OWNS that segment, and has owned it for decades. Even Camaro can only hope to buy into a fraction of that market share. It would be alot of investment for little or no gain, and it would be inconsitent with Hyundai's continual move to drive up sophistication of the brand, not brash muscle car prowess (which Hyundai has NEVER had and likely never will).
Trying to bite into that market share is just flat DUMB. Trying to bite into the 350z/370z market share, certainly punching above your weight - but it's doable at least from a brand image growth aspect. Obviously you're not going to sell as many BKs as 370z's. HOWEVER, you WILL permanently alter the consumer's understanding and impression of Hyundai as a brand BECAUSE of a car like the BK, and THAT is why the car is around.
Quarter you're another one who understands this car very well. If the Gencoupe was to be a muscle car I wouldn't have cared for this car because I never liked muscle cars mainly because of there boxy 20th century type styling. As soon as I saw the concept GC I knew who Hyundai was aiming for and It's sad that a lot of people can't see it like me and you.