For some reason, Swedes seems to generally develop later than other countries top players. The term late bloomer is quite frequently used for Swedish players and we can also see a fair amount of players picked in later rounds (or signing as free agents) being succesful NHL players.
A problem has also been coaching. The idea of developing and selecting coaches from within the national system. All cast in the same mould, no seldom with no experience of mens hockey. Look at Grönborg, he has never coached a mens team before being named coach for the National team.
One last factor is the lack of winning culture in Sweden, the ability to perform in the most important games. It's just not in our blood.