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
I'm sure there are legions of people too stupid to figure out you need the four numbers to find your friend but if they really care they'll figure it out. I'm sure a ton of people get confused by Twitter since your display name and @ can be different. But even if that's the reason for the change I don't think the internet needs to bend over backwards to appeal to the LCD of idiots.