My opinion on the genre of multiplayer VS is that players are not supposed to win as they are in other genres. The focus in every other genre is to have the player beat the computer and succeed. However in competitive games the entire goal is for one person to win and another to lose. This can become a very frustrating element that causes players to quit.
I think a “good game” in this genre gives both good and bad players an equal chance of being able to win. Skill should not be the entire experience of this kind of game. That is when the game becomes impossible for the common player. If the game is in the case of tournaments when professional players are involved, I think then there is an exception. This is when the game should involve entirely skill for the players. Games like Smash Bros or Halo (1,2,3) have items and during these competitions turning them off would balance the game.
I think that Smash Bros, Mario Kart, Halo (1,2,3) are good examples of games that allow all skill levels as well. Like I said before I think that this is the case because players of good and bad skill level are able to play together. After which point both players can enjoy the game and stand a chance while playing together.
I think games that are bad at balancing good and bad players are most fighting games like Tekken. Not that these games are bad, however in a lot of cases players can become so good at the game that the match ends after 1 hit. Then the experienced player will be able to chain an infinite combo. This makes the game hard for newcomers when playing with an experienced player. Playing the game online proves shows only the best survive.