If I remember, it was a matter of money. Sterit was asking for 4M$ at the time. It seemed a lot but his years after the Habs proved they were wromg letting him go. Habs suffered not having a D like Streit for years.
Oh stop it.
Subban debuted 24 months after Streit was gone.
Streit was a bad fit because of Markov and Hamrlik who were both rocks on the left side. At the time, Habs also had two very promising Ds, and one of them, McDonagh, was a lefty to boot.
Habs needed Streit to either play D on the right side where he sucked defensively or on offense.
Bergeron and Wiz both had success being used in Streit's spot following his departure and then Subban came in, so there was hardly any lag time to fill that role. Whatever dip the powerplay had, had more to do with Markov missing almost two years.
Streit was a midway occurence of a string of PP placeholders next to Markov who've had success.
Souray, Streit, Wiz, Subban
Schneider and Bergeron to a lesser extent.