I've been playing many online matches and out of these matches, when I played as Naruto they would quit or put titles such as "No Naruto" Anyone care to explain?

Allow me to explain. Most Narutos (that are most likely beginners or do not play at a serious level) tend to overuse/spam all of Naruto's special moves, namely Clone throw and aerial Down-Special. Its very, very annoying to play against, and its frustrating when you may have higher skill level but you lose because they just kept throwing clones and were unable to react properly due to match up constraints, input lag, lack of experience against spamming, etc. Naruto's overall control of the pace of a match can be abused quite easily in online mode, and while I'm not assuming you play like this, many people will assume it and attempt to avoid Naruto altogether. I personally do not like this playstyle either, but its something everyone deals with. Don't sweat it too much.

Naruto is the gayest character in the history of gay.
And i play pretty gay
But i cant outgay a naruto no sir.
Playing against naruto is like getting bombarded by a hoard of flying bricks.
Really loud and annoying flying bricks.
Bricks twice my size
Bricks twice my speed

f*** naruto

Pure poetry.

The johns are real

Basically what Sorabotics said. Playing against Naruto while dealing with some lag is extremely annoying as the lag messes up your reaction time on the clone throws, and because it has decent throw back sometimes you cant recover quick enough before the scrub is throwing another one.

Also, I know this sounds kind of terrible. But I honestly think they pick the lagiest stages cause they know. :[