brawl has 35 characters.long post that ignores obvious math principles.
melee has 25 characters.
Chances that certain characters are going to be better than others in most fighters?
I'll list you some examples. 56 characters in marvel vs capcom 2, 4 make up most team combinations. 19 tournament played characters in 3rd strike. 3 make up most tournament top 3 placings. Street fighter 2 turbo, 12 characters (not champion edition) and only a couple were placing high (until sagat got banned/depends where u played the game).
Do some rough math and you'll see that 10ish% of character viability is good. The unique method of how brawl matches work out allow many characters to be useful in tournament. However, since MK works so well all around and everywhere. Players would rather not be counterpicked at all and simply choose MK.
I believe this game has some the largest character playability than any other fighter; without Mk involved. How many times have you played a tournament match whenever someone loses the first round with their favorite character and plays MK throughout the rest of the set? It gets old.