I can understand that not having your favorite character in kind of sucks. Believe me, I get it.
There is nothing wrong with being dissatisfied. As always, if you don't like the DLC, don't buy it. That's why, unless you travel and compete, DLC is completely optional.
These people wanting to drop the game, stop playing competitively, sign petitions, so on and so forth I don't get. These people saying the game isn't MK because of guests, I don't get. The series has always been over the top and silly, or are forgetting that they had a whole feature where characters could turn into skunks and dinosaurs as finishing moves. Or that in older games, you could give your opponent dolls or birthday cakes as finishing moves.
Point is, this series has never taken itself too seriously.
Presumably, most players have a main by now. Either a character they like or a playstyle they're fond of.
So...why don't you keep playing your main?
Does KP2 stop you from doing that? At all?