Not to provoke anyone or sound like an ass, but all this complaining about ninjas in a Team Ninja game just sounds.. contradictory. There are a lot of fighting games with less ninjas that you would probably spend less time complaining about. One of them even has similar mechanics!
Again, I'm not trying to bash anyone. But isn't it kind of a given that a large amount of people will flock to the ninjas when they were intended to be the selling point of the game? If this is too hard to accept, I have bad news. The new Team Ninja plans to merge the worlds of DOA and NG even further o.o Momiji would almost certainly sell a shit load of more copies than another Rig or Mila. Be happy both of them aren't fucking Ninjas.
To reiterate, I'm just intrigued that the same people who bitch about the game in general are now bitching about too many ninjas in a game designed to be centered around ninjas.
Please consider your alternatives. DOA will always have ninjas on its cover, at the top of its tier lists, and in the bulk of the story. Do you complain like this in other forums as well? IIRC, the Mishimas are at the top of the tier list in Tekken, a game designed to be centered around the Mishimas, and there's a shit load of them as well. Ryu seemed pretty good in SF4. The ninjas are the Mishimas of DOA.
Lastly, it has actually been a pretty long time since a new ninja was introduced to a DOA game. Correct me if I'm wrong as I am admittedly new to the series.