I wish more fighters (I think MK had it correct me if I'm wrong) were not only server based instead of p2p but have servers full of people at various skill levels. Because if someone is at a rank of 16 or 20 it rarely means anything, they could just be another dude picking shoto and running away, spamming fireball, and abusing that half second of lag.
Where you have a newbie server, an intermediate server, and pro server respectively.
Fighting games are 1v1. You can send the gamestate data directly to and from both players.
Whats the point of adding a third party into the middle? (the server). It just adds more latency. Peer to Peer is the best system for 1v1 netcode. (unless there are other issues like tracking disconnections and spectators.)
What you might mean, is having a server for the matchmaking. Actually most games (including KOF13) use a server for the matchmaking (Sony or MS's, respectively.) But the functionality offered by Sony/MS for this kind of stuff is really primitive (Ranked/Player/Create, as we've seen in countless games).
So what you're actually asking for is that more advanced functionality be made for the matchmaking, like dividing players into channels and so forth. In which case I agree with you. But its not a matter of server-based vs. p2p.