Blaming trhe coach for all things and failure is too simple. Everybody knows there are eveal ills plaguing the Indian cricket. Gavaskar's criticizm appears more personal. He has not not given his reasons.
In any even having appointed him as coach, blaming him personally is not a sign of maturity or decency. Having appoited him, we should take responsiblity for that as well (even if things were wrong). He has had the courage to own it up and leave.
