Injuries mainly. And from that, extended losing streaks. Their top scorer, Tage Thompson, had a wrist injury he tried to play through, but his scoring was cut in half. Dahlin also had lingering back spasms.
Since Ralph Krueger left the Sabres can't put it all together at the same time. Good goaltending? Can't score. Got even-strength scoring? Power play sucks. Certain key players, like Jordan Greenway, can't seen to stay healthy.
I think the reason they are staying with Adams is because the Sabres actually have a pretty talented roster. Thompson, Dahlin, Tuch had good years stat-wise. Trades and free agent signings like McCloud and Zucher turned out good. Young players like Kulich and Benson are starting to emerge. The Rochester Americans, who are currently in the AHL Calder Cup quarterfinals, are loaded with prospects.
So why didn't they make the playoffs this year? Terrible defense and poor goaltending that resulted from that. There was a disconnect between the players and head coach Lindy Ruff on how he wanted them to play.
Then there was a 13-game skid in December (10 L, 3 OTL) that dug a hole they couldn't climb out of. Having Dahlin out (back issues) didn't help.
But they did play better the last two months and they must feel like if they can just maintain that the entire season they will break the drought. Having blown to up the team three times in this 14-year drought, I think they believe they are close and blowing it all up again will just add more years to the drought.
Bills fans know what a playoff drought is like. And in 2017 no one expected that drought to end. (It took a Bengals miracle to happen.) But it did end, and look at the team now. You gotta believe the Sabres will find their way out.