For the life of me, I will never understand how developers, of all people, see “just take ownership of system directories, which we will relentlessly pollute” as acceptable behavior for homebrew.
I don't think this is a fair characterization: on Intel, Homebrew uses `/usr/local`, which Apple has (historically) left empty as a location for non-OS managed software to be placed. To my understanding, this is an artifact of macOS's partial BSD ancestry. On ARM-based Macs, Homebrew uses `/opt` to avoid even this confusion (a trait it shares with other non-OS software but administrative-type software).
On the other hand, if Homebrew used `/usr` by default, this would be a fair characterization. But it doesn't.
But the problem is that /usr/local/bin is in the default PATH. They defended this discussion to take over until Apple silicon came and they “silently” fixed it avoiding admitting anything wrong in the beginning
I don’t really understand what the problem you’re referring to is: /usr/local is explicitly the non-OS software hierarchy, which is why Homebrew used it. When Apple Silicon came out, the prefix was changed as part of allowing native and Rosetta-driven Homebrew installations to co-exist. There’s no nefarious reasoning behind it.
Edit: a thread with a bit of the history can be found here[1].
The really shameful behaviour at the time was that if you changed it (which you theorically could), some packages were so poorly written than they just broke and homebrew just warned you it was going to be this way instead of actually fixing the issue.
Flabbergasted.