Does that surprise you?
While I do agree with sithara's argument of unpredictable nature of T20 format but I bet if all test nation teams start playing associate on regular basis or let's say for world cup qualification then Bangladesh would be best candidate to shit the bed.
Bangladesh performs poorly while playing in SENA countries, partly due to the fact that they don't have neutral tracks at home, and perhaps also due to the fact that their players hardly ever feature in franchise T20 leagues outside Bangladesh. The player pool is quite limited, and in this characteristic they are similar to associate nations such as Namibia and Nepal. On top of that the BCB doesn't know how to groom their promising players. Once in a while they get players such as Shakib and everyone knows how he was treated by the BCB.
Players are lazy but credit for all the fuck ups goes to only BCB.
Franchise cricket and IPL is nice way to gain experience but the way this board treats NOC issue for its players is embarrassing. They don't say no to them but they don't give green light to their players either. One of the reasons franchises in IPL never go for Bangladeshi players unless it's extremely necessary, they just stopped trusting them and in many ways it's harming the players.