hmmm, sounds like you could be talking about a Morgan, bar the off road bit hehe. Lack of shoulder room, can't ignore the limitations etc, perhaps why I love them

I would say the same if MMC started buying back pre-CX traditional Morgans, adding a larger engine and auto-trans and charging £190,000+ for them.
I'd take a pre-CX standard Morgan (a Plus 8 if I wanted a V8) for £30,000 instead of a 'do-over' for six times the price!
I like the 2016< Defenders but I've always struggled to see the appeal of modifications that try to turn it into something it isn't. Improving the interior, suspension and remapping the 2.4/2.2 diesel engine to improve performance and smooth out the 'kangarooing', I understand. However, all of that can be done for under £10,000 easily AND that would be with great components.
Using your Morgan analogy, which I'd agree is fair, the same could be said and much of it is documented on this forum - people spending thousands to improve brakes, suspension and amending various aesthetic elements to their own taste; nevertheless, the issue is they spend thousands of pounds, not 400% more than the donor car.
There will be a market for these 'Classic Defender V8s' but it will be small and certainly isn't aimed at the people the original Series and Defenders were designed for imho.
Each to their own and because I have a great affinity to the Defender, I'm not knocking the base vehicle, but I do find the end product - in this instance - incongruous to the original on which it is based.