Tamim Iqbal is not too old. He could easily have continued playing in the T20 format for another 3/4 years. But I don't understand why he is thinking of retiring now. Bangladesh is yet to find a suitable replacement for Tamim Iqbal. There is no good opener in any Bangladesh squad. So if Tamim Iqbal retires now then the Bangladesh team will definitely face a problem. Tamim should be with the team for the next World Cup.
Tamim Iqbal is one of the best product from Bangladesh in cricket, and he plays some good innings for his country which was honor for player like him and if he announces this then surely we need to respect his decision because he feels in this way which is good for youngsters, and he wants to concentrate on two formats which is also good for him after the worst start of West Indian tour then end in amazing way which is surely a proud moment for Bangladesh cricket now they are second in ODI League table behind England which is another milestone for them.
Even he already announces about retirement from T20i but still he needs to give one favor and if he announces after T-20 world cup this could be better, but he already announces so no one can do anything right now with his decision.
Tamim Iqbal is a very nice player. But bangladesh team has always remained in criticism.
If he has done this decision - we must respect his decision.