When I sold PC hardware, I'd try to find the right fit for a customer's needs and pricepoint. Way back then, that often meant selling systems with relatively-inexpensive Cyrix or AMD CPUs and more RAM instead of systems with more-expensive Intel CPUs that had less RAM at any given price -- because those were good tradeoffs to make. By extension, I did a very small part to help foster competition.
But gamers drive the bulk of non-datacenter GPU sales and they don't necessarily act that way.
Having observed their behavior for decades, I feel confident in saying that they broadly promote whatever the top dog is today (whether they can afford to be in that club or not), and aren't shy about punching down on those who suggest a less-performant option regardless of its fitness for a particular purpose.
Or at least: The ones who behave this way sure do manage to be loud about it. (And in propaganda, loudness counts.)
I suspect they'll be fawning over nVidia for as long as nVidia keeps producing what is perceived to be the fastest thing, even if it is made from pure unobtanium.
