Why is disrespecting proper Fullscreen Alt+Tab and Alt+Enter Behav."Work.as.Intend."?

Hi there,

I am frustrated with the game client not sticking to operating system conventions..and even more so after i found this post under "working as intended"
https://forum.square-enix.com/ffxiv/threads/267628

That the game client does not respect the proper Behaviour of using ALT+TAB and ALT+Enter and Minimize, or even the "Show Desktop" to switch to the Desktop and/or windowed Mode is really filed under "Working as Intended"... I can see no reason on the planet why this should be the case.

It is WRONG, its against all windows conventions and its ANNOYING as hell!!

Im an adult and i have things to do on my computer aside from playing the game and i want to switch properly without the game coming up again whenever i try to select something else, or MINIMIZE it, without having to do tedious steps to change the i it to window mode and change it back manually. Why is that so difficult to implement or even unwanted???? I am certainly BAFFLED by such indolence towards the user.