What is the reason Pep Guardiola leave Barcelona?

Many people specially the fans of Barcelona asking the reason. Why Pep Guardiola leave Barcelona? In my opinion, if you see the match Barcelona Vs Chelsea in Champion League or Barcelona Vs Real Madrid in LaLiga. You should know exactly what His reason to leave Barcelona. Not because Barcelona lose in that match, but more because of the trick that they have used. Both team, whether Chelsea or Real Madrid use some coward scheme. Usually, most football team use 4-4-2, 4-3-3, 3-5-2, 4-3-2-1, etc. It will guaranted a wonderfull match, like usually we saw when Barcelona played. But try to remember what Chelsea used on the Champion League recently! They use 9-1 scheme, cause they only think about winning the match. So they forget the beauty of football, the rush, the tempted, etc. When its success, Real Madrid adopted the scheme and again we only see a boring match. So in my opinion, if Pep still in Barca the art of football will disappeared slowly but sure. Cause every team whose meet Barca, will adopt those scheme. Even worse if every lower class team on every league will adopt that scheme when they meet the highest class. Could you imagine if that happen? But personally, I admits that Pep was a genius. He is the only one who able to make such a great team like Real Madrid or even Jose "selfiss" Mourinho become nothing but a bunch of loser. Carry on Pep!!