It was mostly gamers. As a gamer from that time, the hardware was marketed to gamers, hard. I don't doubt that artists had an impact, but the world had many, many more gamers, than artists and gamers spend money for the best/mostest/etc.
I mainly know this from living through the CGA/EGA/VGA/SVGA/3D add-on card/3D era.
Thank you for taking the time to delve into this. While I may not agree with your conclusions, I respect your work, and the effort put in. :)
Edit: this discussion is interesting because I have always just taken it for granted that video games are a form of art. Clearly others don't see it that way, which is fair! Nevertheless, I think a strong case can be made: https://en.wikipedia.org/wiki/Video_games_as_an_art_form
Gamers aren’t primarily spending time or money for the art and neither was NVIDIA. I will grant that the hardware improvements did make the visual aspects more lifelike and detailed and that allowed for increased artistic range, but production costs generally increased accordingly.