If the play were called correctly, the Chiefs would have had another chance to attempt the kick. Perhaps Ryan Succop would have made it, perhaps not. But they should have at least had another chance, if the play were called 100% correctly.
If the Chiefs were successful in their 2nd attempt, they would have won the game. That would have actually given the Pittsburgh Steelers a playoff berth, since they needed a San Diego loss.
Now, Steelers fans are all over it, whining about why their mediocre 8-8 team should have been handed a playoff spot. Even Steelers players are in on it, like defensive end Brett Keisel:
When is officiating in the NFL going to be judged the same way we are judged as players.Mistake by player Big $$! Mistake by official..Sorry— Brett Keisel (@bkeisel99) December 30, 2013
Maybe if the Steelers hadn't started the season 0-4, they would have made the playoffs.
Maybe if they didn't lose 21-18 to the Oakland Raiders, in a game in which they only managed a single field goal in the first three quarters, they would have made the playoffs. Perhaps if Ben Roethlisberger had managed to do better than only 1 TD and 2 INTs against the league's 28th ranked passing defense, they would have made the playoffs.
Perhaps if they had beaten the Miami Dolphins, another non-playoff team, they would have made the playoffs.
Basically, if the Steelers had been any less mediocre at any point in the season, they wouldn't have been relying on the Chiefs' backups to beat the Chargers just to get the Steelers into the playoffs.
Would Succop have made the re-kick? Probably. But is it a guarantee? Nope. And was the penalty really THAT egregious? Honestly, I don't think so. Illegal, yes. But did it affect the kick? Would anything have changed if one more player was lined up on the left side of the ball? Probably not, realistically.
The bottom line: Humans make mistakes. Much like boxers should never leave a fight in the hands of the judges, an NFL team should never leave their season in the hands of another team. Or the refs.