Actually, it is in considerably wide use for desktop linux applications. It definitely has tangible benefits as well -- it promotes the clear separation of app

Actually, it is in considerably wide use for desktop linux applications. It definitely has tangible benefits as well -- it promotes the clear separation of app data and user configuration, and unclutters the home folder. And as pointed out by other replies, ~/.local is not the only XDG data dir. I'm curious, how do you find it not easy to implement?