Agree that this is pretty ridiculous, requiring 138% more power (238% total) to achieve a very minimal win. And as another person pointed out, that's not even including the undoubtedly massive amount of power for cooling.
As for these selling because AMD chips aren't available, these will sell regardless, because a) people are more familiar with the Intel brand, b) Intel is more prevalent, and c) Intel uses, and has used for many years, anti-competitive practices to help push their products over AMD, hence (a) and (b).
And if Intel could take the same exact design to a 10nm or smaller with no other changes, it would absolutely result in an improvement, due to lower power requirements, which would lead to both less power consumption and being able to run faster due to less heat, and less time for the electricity to move through the processor. Granted, these changes wouldn't be major, especially the latter, but they would be there. More importantly, they could add more transistors in a given size, which would result in a more significant performance increase. To me, the fact they've managed to do as well as they have on 14nm, competing with TSMC's 7nm, tells me they have a highly optimized design, but they've squeezed about as much out of it as they can and they really need to shrink their die size, but doing so would likely result in a pretty good performance jump. Again, nothing earth-shattering, but probably fairly substantial.
The thing is, it doesn't matter if it would result in a 10x increase; the bottom line is where they are now, and right now, they're not doing well against AMD. That may change once they get 10/7/5nm figured out, but that's something to be determined once they get there. For now, 14nm is what they have, and it's struggling to hold its own, period.
Some people need TB or other Intel-specific features, but for most people, it's really hard to justify Intel over AMD right now, considering you're getting barely better single-threaded performance, much worse multi-threaded performance, and using more power. But chips shouldn't necessarily be compared based on tiers. ix != Rx necessarily, and it can go either way. People need to look at them based on cost, because, e.g., a $400 i7/R7 vs a $700 R7/i7 are not in the same category and shouldn't be compared against each other, whereas a $400 i7/R7 should be compared to a $500 R5/i5.