AMD is struggling to sell its RX570/580 at massively discounted prices despite being much faster than anything Nvidia has to offer at those price points and now AMD launches its new GPUs that are barely faster than Nvidia's year old GPUs while drawing ~50W more at about the same prices. Can't imagine how AMD imagined this being any good, ...
The math is simple: If cutting the prices doesn't increase sales, don't cut the prices!
The Vega cards will disappear from the market, so those are a non issue.
With Navi slightly faster and cheaper than Nvidia's competition it could be a win, though I expect Navi to behave much like Vega when it comes to tuning voltage and frequencies.
... Not enough. People expected more.
Ryzen 1xxx & 2xxx, same thing, but competing with Intel. Didn't blow 'em away either, but great price for the performance you get. Again, not enough. Some people were still disappointed. More, moar...
Well,
some will never be satisfied. Sales figures still show that enthusiasts buy more Ryzen than Intel's Core options, so obviously not that many are disappointed.
... very few people will bother upgrading for 10-20% more performance, even more so if they have to spend 10-20% more for it.
So what? I don't expect anybody to buy a new card every year. The only reason to replace a relatively new graphics card is if the needs differ, like if you've happily enjoyed gaming on a 60Hz 1080p monitor using a Radeon RX570 and now bought a 144Hz 1440p monitor.
Then a 20% increase in performance is insufficient, but you also expect to pay way more for the required ~400% increase in graphics performance.
At more heat, noise & NO tensor cores, it will be a very hard sell.
Have you tested these cards yourself?
I'd wait for hands on experience or at least some unbiased reviews before jumping to any claims on heat and noise. I also expect Navi to favor lower voltage like Vega.
And tensor cores are useful for what? I've been under the impression that their only use in gaming is to either reduce the image quality (DLSS) or heavily reduce the frame rate (ray tracing)...
And their fan shroud engineer needs to contact me. There are some basic changes to the design they could do...
I wouldn't bet that your proposed changes haven't been tried/evaluated and either rejected (for good reason) or implemented (but not clearly shown).