AMD's GPU OpenCL wasn't just not marketed, it was also a bad product, even for relatively tame scientific purposes, even when AMD made loud, repeated statements to the contrary. Hopefully now that AMD has money they can do better.

I'm sure that NVidia's ecosystem building played a role (I remember events in 2009 and books before that), perhaps even a big role, but it wasn't the only factor. I paid a steep price in 2014 and 2016 for incorrectly assuming that it was.