Better question is: Why do those who support it act like it's going to make or break the game and absolutely demand an answer from SE for their reasoning of saying no? Normally JP developers never say 'no' outright, but it's clear there's just no plans for this. It's honestly not that big of deal and it truly was this "standard" feature every MMO from 1993 - 2014 would have it.
Every single one. What SE is missing that's standard, though, is transparency settings.