Not lion's share but some of it. Sabres screwed up a lot. Mistake #1 might have been expecting Jack Eichel to do what Josh Allen did for the Bills.
Jack's true nature was on display in that post game. He doesn't have the character to lift a team. I always said the difference between Eichel and Allen is one guy was doubted his entire life and had to fight for every inch of success. The other guy was the golden child. Treated special. Always on elite teams.
And when Jack ended up in a less than ideal situation he didn't know what to do. He sulked. And that sulking affected the locker room and it became a vicious cycle.
Not everyone is born to lead. And I'm not absolving the Sabres. They kept hiring coaches and managers who were married to systems. The difference now is a coach like Don Granato looks at what players do well and puts them where they can do their best.
But that game, that win, how it happened and what Jack Eichel said, was what the Sabres needed to turn the page on the last ten years.