Real sports have a defined ruleset, but the human element and individuality of players/teams are what make them so interesting to watch. e-Sports players are not only bound by the ruleset of their particular game, but also the constraints of the game engine which is why in almost every game there are "optimal" strategies that everyone follows with the only difference between players being the execution of that same strategy.
For example, for the majority of football teams the most efficient way to play might be to smash long balls in the air up to their 6 foot plus centre forward, the same way the most efficient way to play League of Legends is to run a 1/1/2 lane configuration with a jungler - the difference is that when you get to the higher leagues only a few football teams actually play that way because of the human element.
The individual characteristics and strengths of their players lead to completely different styles of play - Bayern Munich for example have a lot of extremely talented, fast attacking players so they pressure very, very high on the pitch and try and win the ball back before it ever gets close to their defenders while Barcelona have a midfield stacked with excellent playmakers and so they focus on a lot of short passing sideways and even backwards to wear down the other team's discipline and open up attacking gaps in their ranks.
Going back to the League of Legends analogy, the difference between any two professional teams is minor at best. Some focus slightly more on farming and teamfights while others like to press the action earlier but at the end of the day they are all doing the exact same thing with the same lane setup, the same characters and the same plays being made. Even looking at individual players within those teams, the difference between any two given bottom lanes is just mechanical skill in the game engine as opposed to styles of play with varying strengths and weaknesses.
TL;DR e-Sports are crap