Adding four random digits to people's names was a brilliant solution to two common problems with usernames (users wanting the same username and usernames of notable personalities getting leaked), and now they're just going to the exact same system everyone else uses with all of its attendant problems? Fuck off
But they've explained exactly why they don't think the system they're fucking with works well. This isn't just a case of changing stuff to change stuff, they're changing something which is problematic to address those problems.
Also notice how at first you were like "they're not more complicated" and now you're like "ok they are more complicated but it's worth it"
Discord doesn't think it's worth it. It's as simple as that. Now you understand what they were thinking. But keep moving the goalposts.
I've never denied this. I've only said that I do think it's worth it, and that I find Discord's explanation lacking.