Because the Broncos have a backup QB

The question: why can't LoL be considered a sport.

We've all played with someone that had a "bad connection", resulting in that person having frequent lag and/or disconnects. Or perhaps a disconnect at the beginning of a match that they can't recover from.

In a sport, such as football, we would call this an injury. If Peyton Manning gets hurt, he's taken out of the game and a backup QB is put in his place to keep things going. In LoL, this isn't the case.

When an individual experiences some sort of connection anomaly, he/she is effectively removed from a match but NOT replaced. The result: a 4v5 match. Or perhaps 3v5. Or any number of possibilities with the same bottom line: inequality.

It's because of this very common, very disruptive event that LoL can't be considered a legitimate sport. If a match can't even have a balanced number of players, how can a team be expected to compete fairly? All else equal, the team with more players is going to win. That's very difficult to argue against. Right now, LoL seems to have difficulty ensuring all else remains equal.