I agree. The Sabres' lineup, esp. from about 1996-1999, is the late-90s' equivalent of the California Golden Seals of the late-70s, yet the Sabres had three solid winning seasons in a row, went to the Conference Finals once and the Cup Finals once. There was a reason for that, and it wasn't the coach, the system, the forwards, or the defencemen.
Poor Ken Dryden -- he never gets the benefit of the doubt in threads like this, yet Patrick Roy somehow always does even though he basically spent his entire career behind great teams as well (and Dryden won the international best-on-best he was in, while Roy lost).
Let's take a moment to look at how the Habs did before, without, and after Dryden:
1970: missed playoffs
Dryden joins in spring '71
1971: win Stanley Cup
1972: 108 points (3rd overall)
1973: 120 points (1st overall), win Stanley Cup
Dryden leaves
1974: 99 points (4th overall), lose 1st-round of playoffs
Dryden re-joins
1975: 113 points (tied 1st overall)
1976: 127 points (1st overall), win Stanley Cup
1977: 132 points (1st overall), win Stanley Cup
1978: 129 points (1st overall), win Stanley Cup
1979: 115 points (2nd overall), win Stanley Cup
Dryden retires
1980: 107 points (3rd overall), lose 2nd-round of playoffs
As for "if Dryden played for another team", how about the three years he played college hockey for Cornell Big Red? He went 76-4-1. And he went 16-7 one partial season in the AHL.
Let's show some respect.