There is certain amount of truth in this . Also let me give an example - most of the students are scared of Mathematics - I hope I am right from what I have learnt from my experience . This is basically -at the early stage they have horrible teachers .What with reservations , private institutions ,coaching etc . This is basic step to make students excel or get in to disaster mode. A coach has also same - if he is good and knows the game and also some amount of science - he can guide the players .Also there are times when the morale of the players and confidence of the players is at low ebb here he can help. However finally it is the player who has to do the job on the feild .Say for example in a pitch like Kolkata Eden Garden - what can any bolwer do ? Just boewl striaght and do not try short pitch too much on the dead wicket . No balls - it is a pity becuase it is at prctice sessions one has to learn .here the coach can help.All the same dead pitches dead feiders and bowlers the game is going to be a ritual or process one has to gop though .
Each individual has a talant when he is selected in the team. Coach is supposed to assess the strengths and weaknesses of individuals and put a team perspective to it and identify gaps that could be easily filled in and discuss with the individuals how they can help in executing the plan and help the team. End of the day team does not need to be filled with allrounders like Kallis or Watson.