I agree that we should probably seperate the concerns here. Personally, I like the idea of being able to say "CURRENT_USER" in utility commands to refer to the current user where a role would normally be expected, as I could see it simplifying things for some applications, but that's a new feature and independent of making role-vs-user cases more consistent.
So, I've been doing a little digging and it would appear that the ALTER ROLE/USER consistency was brought up earlier in the year.