There's an explanation somewhere as to why. It has to do with "not breaking" stuff relying on it. So I guess it only answers "why we won't fix it".
Anyway, I don't think this is enough. Or I guess it only works to stop the trigger during install? I have the NO_AUTO_UPDATE set up, and recently needed to update (or upgrade? who knows) a single package and it somehow ended up with Homebrew working for over two hours. I saw it installing python at least two times.
That's not a proper explanation IMO. The thing is - all these settings are introduced "quietly" as new defaults and you have to opt out. So one day you decide to upgrade a package, brew updates itself, and then starts doing all these things that weren't present before (and are most likely not needed at all).
It's very annoying, and a dark pattern to say the least.
Anyway, I don't think this is enough. Or I guess it only works to stop the trigger during install? I have the NO_AUTO_UPDATE set up, and recently needed to update (or upgrade? who knows) a single package and it somehow ended up with Homebrew working for over two hours. I saw it installing python at least two times.