OP is not asserting that all GPL'd code is part of the "gift economy". I also wrote some GPLv2 code a large corp in the past, and I wouldn't consider it that, either. But projects like UBlock Origin that are run by volunteer contributors are very different.
You seem to be basing your rejection of "gift economy" as a label for the latter on the basis that it's not done for entirely altruistic purpose. But that is generally true of gift economies - most people who participate in them (and I'm not just talking of software here!) are not doing it out of purely altruistic motives, and actually expect to receive benefit from such an economy as well. Usually this is cultural, but some people, like you, might consciously believe that it's the most efficient way to distribute goods (whatever their definition of "efficient" might be).
You seem to be basing your rejection of "gift economy" as a label for the latter on the basis that it's not done for entirely altruistic purpose. But that is generally true of gift economies - most people who participate in them (and I'm not just talking of software here!) are not doing it out of purely altruistic motives, and actually expect to receive benefit from such an economy as well. Usually this is cultural, but some people, like you, might consciously believe that it's the most efficient way to distribute goods (whatever their definition of "efficient" might be).