no question about it, when you play the arcade and reach the final boss it's gana be clear your fighting a character that in generly stronger then the rest of the opponent you had  to fight to get to the final stage , but what reason were some of these guys even chosen to be the final bosses? are they simply the strongest  characters via canon wise?

lets take a look at the original Street Fighter II , Bison (Vega in Japan) is known as the strongest before there  was any Akuma, when Akuma first made his debut he one-shot Bison with the raging demon , so now we assumed his the strongst fighter and so, he became an extra boss, but when it comes to the canon, he didn't really show up as a final boss, only fought bison after the end of the tourment .

but lets take a look at  a game like Power Instinct Matrimelee where Princess Sissy was the last boss, and even tought she is annoying to fight , I still don't think she is the strongest character when it comes to Canon ,, so why is she the final boss then ?

I guess it depend on how they effect the story line , regardless of their power level in canon

Now try reading the question.

maybe every fighting game from now on should look like this
http://www.youtube.com/watch?v=7pnsJKfcz3Y

no characters with personality or story what so ever , as long as the game play is balenced, who cares if the female cast is voiced by guys , or look all the same .

kof xii is not a dream match game it was a rushed beta