Probably a lot of people have thought of doing something like that. But what would be the purpose? The points don't do anything except tell you how much others appreciate your memes, and if you were voting on your own memes, you'd be taking away from that, not adding to it.
Also, it sounds like unnecessary effort. It's easier to get points on imgflip just by making funny comments or meme comments on front page memes (and that way it's still about other people liking your stuff). That's my take on it.