I had to delete my comments cause I was getting downvoted like crazy (for no valid reason) but:

I think it's a lot easier to be a casual fan of esports, since matches are a lot shorter and more intense than most sports, and especially for straight fighting games, it's easy to just jump right into a match and tell who's doing doing well without even knowing the rules of the game.

I'd say this is a good point. I assume it's pretty hard to get into American football, baseball, cricket etc. if you don't know the rules. But if you're playing a game like Smash Bros I assume the rules are pretty clear and the matches are short.

One thing I doubt will ever happen with esports is it being integrated into entire communities (towns, cities etc) like the EPL does, or Mexican soccer, or Texas Highschool football, or Japanese highschool baseball. I'd be extremely skeptical of entire communities revolving around video games in the same manner. Which is why I doubt it will ever reach the tradition that many actual sports live on.