This isn't a standard, it's a convention at best. A freedesktop.org specification. Basically a scheme Red Hat people thought up and implemented widely in the open source software projects they control. It may be a useful abstraction but there's absolutely no obligation to conform to it. There doesn't have to be an "excuse" or any form of justification at all. "I just don't like it" is enough. I don't like those unsightly XDG variables either and it's entirely within my power as a software developer to trash the entire concept of XDG and do things in any way I see fit.
https://www.freedesktop.org/wiki/Specifications/
> freedesktop.org produces specifications for interoperability, but we are not an official standards body.
> There is no requirement for projects to implement all of these specifications, nor certification.