Shameless plug: I am the author.
And if I don’t agree with how that standard is implemented? I should have the choice to use something else. Isn’t that how everything works?
You can of course not give users a choice. And a lot of applications do their own thing, having their own variables like GOPATH
or a cli option like --config
or some way to do that in a config file like Idea IDEs. But implementing XDG from start is miles simpler for all parties, it’s good practice to have your paths and variables somewhat organized in code anyway.