It's due to a messy combination of software limitations and things we need to do to make sure people can't abuse the name changing system easily. I actually did some reading on the software to see if there was a better solution to our current process, because I don't think it's very good. What I found was the following:
- Without modification, there is no feature to allow moderators (or even admins!) to change any username except their own.
- Users can change their own names when the field is allowed in the software's settings. But again, only their own names, nobody else's.
- The only way one may change someone else's name is by manually changing its entry on the database where all the information is stored.
So given the above, the only way someone's username can be changed is if a) Pokemaster changes it himself or b) you change it yourself when the field is set open. We've tried both, and neither are ideal.
It's a possibility we would leave the name changing field open at all times, but as others have suggested in the comments, it's an easy way to disguise yourself which presents a moderation problem. There's the element that it could end up confusing, and also that you could impostor others easily. Don't think that's ideal either.
So to answer your question directly, this system is the one Pokemaster thinks is best, of a number of options that are all flawed. Bad situation all around.