I think it's also worth noting that the textbooks are typically written by high school teachers and other educators (David Greenwood is the head of maths at Trinity Grammar, Michael Evans works for AMSI in maths education [I think? It was difficult to figure out for him, but I thought AMSI was a volunteer organisation mostly, so], Kay Lipson works for Online Education Services (OES), and Peter Jones I can't find anything about because it is the most generic white-name ever and too many people are popping up). While part of that means they should be able to teach effectively, it also means that they find out the study design at the same time as everyone else. That often means they have only /months/ to put a textbook together, and have you seen the size of these things? They're massive! Of course there's going to be mistakes popping up. It's part of the reason there should be regular re-prints of these books, but I don't think they have this time around, because people kept complaining about the goddamn amounts of re-prints.
I can see why it can be frustrating, but it's important to note that these people are only human. I typically don't like the, "I'd like to see you do better" retort, because it typically ignores underlying issues with things as if to say, "you should be happy with inadequacy just because you can't do better" - because tbh, you don't have to be good at something to know if it's of a poor standard (although some familiarity is required to make proper judgements, see the Dunning-Kruger effect - and any debates on this are best taken to another topic). But at the same time - like, these guys did the best they could with the time they had. Maybe they should've invested in more editors, but it's highly likely the moment they finished writing it went straight to printing. The next point is maybe more writers, but too many cooks spoil the broth, and its important that books like these sound uniform. Like, imagine if you really liked the way functions is set out, but probability was explained in a different way entirely? All of a sudden, you'll be wanting to refer to multiple textbooks, which is just too expensive, and so the textbook is going to lose sales. Uniformity is much more important in this context, than editting, which sounds stupidly counter-intuitive, but it is what it is.
Tbh, we'd be better off with a system in which more time was given between the study design being - well, designed - and then being implemented, just so textbooks had more time to get their shit together, but I can't see VCAA ever doing this.