Re: The history is the best judge
Cyrix was the first one to leave the market. The reason was lack of interest from major OEMs and Intel's shenanigans, locking up Cyrix in court over supposed patent infringement (which was proven to be baseless, but at that time, Cyrix ran out of funds).
You're right that their example is not indication of Intel's wrongdoing. However, it's a very visible symptom. Via offered nice, clean and power-efficient x86 CPUs and pushed interesting new form factors. Left to their own devices, they could have carved a niche in HTPCs, low-power desktops and laptops as well as home servers.
No OEM picked them up, Via effectively disappeared years ago. While planning my first NAS box seven years ago, I was looking for them, and they were only available imported, in very limited quantities and with implementations that left a lot to be desired.
Transmeta -- I've seen only one laptop offered with an Efficeon CPU. It was interesting, but laptops were out of my financial reach at the time, so I never got one. Still, it got several reviews which rated it pretty well, especially for the price. One area where it stood out was power efficiency assuming light-average use. Trying to force it into heavy workloads and efficiency dropped off a cliff -- performance tanked and power usage shot up. They would have been excellent CPUs for low-power devices assuming they could compete on a level field.
As for AMD, they have the edge in price:performance and always had. Even when they offered $1000 CPUs, they were significantly faster than Intel's equivalents, and afterwards, they continued to offer higher performance at lower price points than Intel (where Intel continued and continues to offer a high-end consumer CPU for $1000, AMD had to give up that price spot for years now).
Even four years ago, which was AMD's worst year in terms of performance, it was still competitive with Intel:
http://news.softpedia.com/news/Blind-Test-Shows-AMD-Machines-Run-Better-than-Intel-s-248202.shtml
In the high-end comparison, it was AMD's first generation Bulldozer vs. Core i7-2700K.
In the mainstream, it was AMD's Llano APU.
Both of them were widely considered inferior to Intel's offerings in "professional reviews" based on benchmarks, and the first generation Bulldozer required several iterations for the highest spec version to be considered competitive with Core i3, maybe i5 if the reviewer felt generous.
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If anybody considered Intel to be an upstanding paragon of virtue in terms of fair competition, I have a bridge to sell you in London.