Of course it's not always an installer, there are "portable" zips on Windows as well The dmg makes sense this way- you can have some filesystem-specific tricks

Of course it's not always an installer, there are "portable" zips on Windows as well The dmg makes sense this way- you can have some filesystem-specific tricks in your app (special links) that might not be zippable, so you need dmg that is a more compatible container. And deleting the app shouldn't clear everything (like user config) without a prompt, but otherwise it's indeed a big issue in how all the OSes are designed.