I mean, for a long time the situation was reversed.

Huge gaming demand and easy retail availability of nvidia's cards was providing economies of scale. If a few professors were buying the GeForce 8800 to look at this new 'CUDA' thing that was mostly a marketing thing.

Around the same time there were also one or two Playstation 3 clusters - but a year or two later Sony removed support for that. HPC being inconsequential, and a distraction from their core business, presumably.

It's only in recent years the stuff that used to be marketing decoration has become reality.