Right, I wasn't speaking of Carmack as part of the trend. Carmack still has an old-school relationship to support of open source. I was speaking about the increasing number of people opposed to open source, saying things like that it's clear that the reason someone supports open source is because they "work for a mega tech corp", you illustrated the trend I am speaking about, precisely. Support for open source is now seen as the side of "mega tech corps", and in fact open source is decreasingly popular in online developer communities. With people accusing those of supporting it of doing so only because they have been bought off or tricked by large corporations. Exactly. This is a change.

The crux of his argument seems to be that he wants to be able to copy and paste other people's code and create derivative work without the GPL carrying along.

Well it’s also because we didn’t see much done with the GPL’d source releases for his engines, just small improvements and standalone mods (The Dark Mod, Xonotic, etc)

No commercial game developer is willing to ship a game with GPL’d code because the license is incompatible with most middleware and console SDKs. We missed out on what could have been a free and open competitor to Unity or Unreal.