I would disagree, files that the user cannot edit or should not edit should not be going into their home directory. Things like cache files should go into a system wide cache directory instead.
Isn't that very anti-linux though, to have a directory owned by root but populated with subfolders owned by other users? /home is the only exception I can think of that does this.
True, but /usr/home is no longer a common place to store home directories. It used to be, particularly in Bell Labs Unix. (Does FreeBSD still do this?)
The Linux Foundation’s File Hierarchy Standard puts user homes in /home, but it’s by no means mandatory.
/home being the *nix home folder directory isn’t written in stone, but plenty of software expects it. Of course you shouldn’t hard code things like that, but that has never stopped anyone from doing it. (Not that we should reward that with de facto standards necessarily.)
I understand the various reasons why a root file system hierarchy isn’t part of the Single UNIX Specification, but it might have been nice.
If I uninstall ssh I still want to have have my authorized hosts. If I uninstall some firefox version firefox I want to keep my profiles. XDG defines a thumbnailing hierarchy followed by multiple libraries, uninstalling any of those shouldn't clear thumbnail caches.
Persistent user-specific state needs to live in a persistent user-specific location. You could choose not to use the concept of a home directory, but you would be doomed to reinvent it.
The fact that nobody does that is pretty much a consequence of the difficulty of coordinating multiple projects that do not have a common authority, not because it is a bad idea.
I agree cache file should not go into their home directory, however I don't agree they aren't user data and that they would be part of the software installation.