No- it is not the coaches fault.
The problem is that the Bangladesh players are talentless except for two players. These players will struggle to play for an english county teams second 11 or a Pakistan s domestic side.
To be honest, i seen street cricketers in Pakistan that are much better then international Bangladesh cricketers. I am not trying to take the mick or act arrogant but this is the truth.
What do you expect the coach to do with a talentless bunch?? Change the coaching staff as much times as you want but till new, fresh, better talent arrives the results will stay the same.