Who is making the comments you wish to discuss does have a great deal to do with it. I know nothing of OpenGL technologies so I would assume you wouldn't hold my opinion as high as Carmack's or Google employees.
Also, I've followed Carmack's exploits for something like twenty years. In my humble opinion, when he speaks of anything OpenGL I would suggest you listen to what he has to say.
I imagine there are thousands of people who are deeply familiar with openGL whose names you have never heard of.
If you dont understand a subject enough to be able to debate on the points that are being made rather than who is making them you should not be debating it
I just dont think its good practice to disregard someones opinion just because someone you have heard of disagrees with them
Also, I've followed Carmack's exploits for something like twenty years. In my humble opinion, when he speaks of anything OpenGL I would suggest you listen to what he has to say.