Very longtime cricket player here. The reason it has caused such a stir is most fans don't actually know how the rule is written, and in fact that rules held by the ICC (International Cricket Council) and the MCC (English that invented the game) are actually different. By being intepreted different ways, we can get different outcomes. I personally think that Mankading is fine, but how this one was done was dodgy. Perhaps we need rules for a balk like baseball does?
For those who want some more cricket related intrigue
Imagine a batter hitting at .800 for his entire career just echelons ahead of everyone else, and no idea how to stop him. How about aim at his head every time and almost cause a war between two allies.
https://en.wikipedia.org/wiki/Bodyline
Imagine not getting the TV rights for the NFL, so you decide to start your own series, with blackjack and hookers!!! But you actually manage to sign up pretty much the top 20 players in Australia in secret and cause a rift not fixed for a few years.
https://en.wikipedia.org/wiki/World_Series_Cricket