Well sure, many were aware of gamma correction, but everyone's so used with how incorrect compositing looks, that it works "fine" in their mind. And being aware of gamma doesn't mean you truly grok the extent of visual corruption that spreads in images while compositing, scaling, editing etc.

I heard explanations how it'd be slow, or doesn't matter, or what am I talking about, all ultimately variations of "works as coded, won't fix".

There are clearly people at Adobe who are aware of the issue in some capacity, and their efforts have weird specifics, such as... they noticed text anti-aliasing looks weird, so they added an Advanced Control called "Blend Text Colors Using Gamma" option in Color Settings. The bizarre thing is that none of this is specific to text. It's just that text has many small complex shape edges, and you notice it more on text (like Carmack noticed it on the star field). They didn't fix vector art rendering, for example. And the option default is not even the correct gamma for a document, but 1.45 which makes no sense at all. They just "eyed it" and went with it.

There's also a Blend RGB Colors Using Gamma option which is disabled by default. If you enable it, it corrects SOME operations, but not others, with no rhyme or reason. However, you can't really tweak those yourself, because if you do, the settings are not saved per document, they're global. So if you tweak them... then ALL Photoshop files you open will look wrong, because they were originally made for another configuration of these settings. Which leaves you with 32-bit color channels. I have Actions that convert an image to 32-bit to scale, and back to 8/16-bit, just so it's gamma corrected.

It's... a f***ing mess.