It is very simple. The fans expectation is too high. Therefore, their frustration is also at the highend. Wants some head on a platter, overhaul changes. That is not the way to go. Lower your expectation to the reality.
As for some positive lashing to the fans who are calling heads:
I want to see one fan who really expected two rookie in their debut opening in a test and having a century stand. Anyone? That is even at a hostile condition? Now tell me was that above your expectation or not?
Second, coming in to the test, after losing Rasel (who was suppose to get the most out of these wickets), you guys expected to get NZ all out at their place? Come on, be realistic? They did twice. Now tell me was that above your expectation or not?
If any of the answer is "no" then you fall in the category of expecting too high. Bring it down a notch.
Kalpurush bhai,
Thank you for your timely reminder.
(we won three WC matches by the way, two big ones 
)