WARNING: REALLY LONG POST AHEAD
Well, at the highest level of play, in a balanced game we should see at least 10-15 or more characters winning majors or even locals.
this is not even close to true for the majority of good 2D fighting games fyi, unless you count random scrub locals or Japan's 1-game single-elimination tournaments (which greatly benefit mid/low tier). the harsh reality is that for double-elimination majors, 4-7 winning characters once a game has evolved is *much* more common. MK9 & Injustice are not uniquely unbalanced by 2D standards, the way a lot of people on this site seem to think they are.
let me run down some of the biggest/most respected Capcom games and look at the characters that won majors...
SF2 Hyper Fighting (AKA Turbo): Ryu/Guile at the top, then Blanka/Sagat at the next level. that is actually impressive given the game only has 12 characters, i will say!
Super Turbo: this is a lot trickier since the American scene largely died once SF4 dropped; it's tough to say whether Damdai's T.Hawk would still win everything if people like Valle & Choi still played ST on the regular, though long-term Japanese results strongly suggest "no". i will say that the consistent tournament winners at the peak of the US scene were Vega, Balrog, Dhalsim, Old Sagat, Ryu, & Chun. Deejay has started winning big in Japan over the past couple years, but in the US Afrolegends almost always dropped him for Balrog against top players...it's more debatable but i'll count him since he's done well in more than a couple big JP tourneys.
SF Alpha 2: A game dominated by the original "Big 4" - Ryu, Ken, Chun, Rose.
3rd Strike: The Chun & Yun Show, with special guest appearances from Ken & Makoto!
Capcom vs. SNK 2: Definitely a lot more winning characters in this game, although a lot of that is because it has a huge cast and a "Groove" system that essentially multiplies the number of characters by 6. even then, big tournaments most often came down to battles of A-Groove top tier (Sakura, Bison, Blanka, Vega) and a few other teams/grooves represented by 1 or 2 top players (e.g. John Choi for C, Combofiend for K, Buktooth for N, Steve H for P). it was still a very small percentage of the cast, and people often joked that "SNK" should be removed from the game's title given how little their characters did!
Marvel vs. Capcom 2: Do i even need to explain this one? actually, i will say that the "Big 4" in this game is a bit of a myth - in its last couple years it became more of a Big 3 (Storm + Sentinel + Magneto), with Cable & Iron Man as occasional but not consistent threats. Cable really dropped off hard once people like Yipes came along and the game just got faster and faster...
SF4 & its iterations: Vanilla = Sagat/Akuma/Ryu/Rufus/maybe Balrog, though it may be a lot different if we went back and played it now. SSF4 by the end = Cammy/Akuma/Rufus/Viper, with some Adon thanks to Gamerbee. AE = the big 3 of Yun/Yang/Fei along with some Viper/Seth/Akuma. AE2012 = Cammy/Akuma/Fei, with a few others that show up in lesser degrees (e.g. Rufus, Guile, Adon, Seth, Gen)
so, only one of the games i just mentioned has 10+ characters who regularly won legitimate majors (and that's the FG with arguably the largest cast ever), and over half the cast could not consistently win at the top level in any of these games. and these were the biggest FGs in the US during their time, hands down!
tl;dr to MK people - the grass isn't really greener on the other side. learn to have realistic expectations of 2D games in general and don't worry TOO much about your games' issues - every game has huge problems somewhere!