It's pretty much bragging rights. There is no way to tell who is better than who in here. No one will ever feel satisfied with the rankings, and others will come out and say that they are better.
Every player has different faults, and different strengths. They play against different characters controlled by different people in different regions. Not only that, but our own play styles are too different to even compare. One Toon Link could be swift and offensive like Arc the Fallen, and another Toon Link can be campy and defensive like Sheikant and myself. You can't really pick who is better by their play style, so it all comes back to who has the better tournament results.
Even then, we have regions to worry about. If you're the best in the Antarctica scene (assuming there is one), that means nothing if you aren't the best in North America, even if the Antarctica scene is really really good. This means that a lot of players get screwed out of being a top ranked character.
So yeah, ending rant. All it will do is make people argue, since there is no real way to define how good you are while being completely fair to everyone else.