This idea, although a little farfetched, I believe could actually work.
As a user of Meta Knight, along with about four other characters, I really do believe he isn't in another league despite him being the best character. It would only make sense, in a fair world, that the community would have to prove that Meta Knight is worth banning before he would leave the scene. However, this isn't the case, and if we as Meta Knight players really do want him to stick around, I think the responsibility falls on us to prove otherwise, since no one else is going to do it.
Hylian makes a very good point M2K. You obviously have fun with Meta Knight, as do I. That's the reason I play him, and I can understand your reasoning too. But you are the best Meta Knight out there, and as of lately, you're the big authority figure running around telling people Meta Knight is not ban worthy material... People can't help but look at you funny. They have little reason to take you seriously with you "leading the pack" as Hylian put it, and if you really wish to contribute to the counter argument, I think using other characters besides Meta Knight may be the best competitive answer. At least then people may listen to you.