But seriously, I do tend to agree. And many of those retcons can usually be explained in continuity with a little creative story telling (which I find novels do a good job doing many times). And some are harder to explain and you just have to live with the inconsistency.
Despite how the term tends to be used in vernacular (and how I used it above in some cases), a retcon is ideally
not an inconsistency. That's the whole point -- it's short for "retroactive continuity," meaning something that comes along later but fits in as part of the existing continuity as if it had been the case all along. For instance, Kirk never said he
didn't have a son. Sometimes it conflicts with what we believed, but it's explained that we were misled before and the retcon is the real truth.
As for "Augment," there's no reason the term can't have existed before. Just because it didn't come up in "Space Seed" or TWOK doesn't prove it never existed, because you can't prove a negative. And like I said, it's a handy, efficient term that we didn't have before, which is the only reason we need to use it.
But yeah, after 50+ years it's amazing they've managed to maintain one single universe from a storyline perspective. Most other franchises seem to decide it's too much trouble and just do a full reboot. Star Trek really only had one reboot, the Abrams movies, and even those weren't a full-on reboot, but a branch off the original Star Trek universe.
Well, yes and no. My understanding is that Roddenberry considered TNG sort of a soft reboot of the universe, discarding the parts of prior continuity he didn't like and approaching it as a revised draft. Like a lot of creators, he was dissatisfied with the earlier draft of his work and wanted to take a fresh stab at it with the benefit of greater experience. It was only years later, when TOS fans like Ron Moore became writer/producers, that they started drawing more direct continuity ties and approaching it more as a unified whole than Roddenberry had probably intended.
For that matter, even TWOK is something of a soft reboot, playing fast and loose with the details of "Space Seed" for the sake of its own story. Most series fiction back then had a much looser approach to continuity than audiences expect today. Certainly that's true of Harve Bennett's earlier work like
The Six Million Dollar Man, where the series rewrote a lot of the continuity of the pilot movie and often rewrote its own past continuity when convenient (e.g. guest character Barney Miller becoming Barney Hiller in his second appearance to avoid confusion with the sitcom
Barney Miller which had debuted in the interim).
The truth is that Trek's continuity is full of contradictions and different interpretations of the universe, and the only reason we perceive it as a consistent whole is because the franchise pretends it is and we choose to play along. We rationalize and gloss over all the contradictions and fool ourselves into believing the pretense that it fits together. New contradictions feel larger to us only because we haven't had as much time to fool ourselves about them.