Trying to set yourself as the default handler for anything should pop up a system preferences box. Beating a dead horse perhaps but in the Apple world this works quite well: there are various permissions like “read folders”, “capture keyboard input”, “access location” and so on. When a programs wants to use these, all it can do is put in a request, and pop up a dialog box offering to take you System Preferences. When you’re in System Preferences you can look at e.g. “read folders” permissions and see all the programs that have requested this, and you can check or uncheck each program to decide its access. This is how default handlers should work, too (although it doesn’t in MacOS at the moment, probably because they couldn’t solve the UI issue of having a list of every possible file type, each with a sub list of every program that can open it).

If that was what Windows was intending, and Google found a way around it with sneaky automatic API calls, and Windows fixed the exploit which then resulted in those sneaky calls popping open Settings every time, that would be fine and Google would be the bad guy.

Sounds like that was not what happened here, Windows did some ugly hack (up to and including ‘relying on a Chrome.exe process name’, like, come on) and in fact doesn’t even have a “make request then approve in Settings” workflow, so yeah Windows is the bad guy here. Google is still a little bit bad - you’re fucking up my UI by forcing a self-promotion button into my tab bar, that’s not cool - but overall this situation is a point against Microsoft.

(Personally I’m glad the extent of browser wars for Mac is some apps doing some trick to make you choose between “Chrome”, “Safari”, or “the default browser [Safari]” every time you click a link. I want to use the default option every time automatically, that’s what default means.)