Ken Holland was able to preside over turning the core in Edmonton around, so I don't think that the Sabres need to totally start over.
I respect Lindy Ruff for his dedication to the Sabres, but I'd be thinking about a shock to the culture. Fire both the GM and all the Sabres coaches, hire an experienced GM (maybe even Holland), and let him cook. No sense of continuity or business as usual. Any old promises disappear, and now it's about cleaning up the mess. It's up to the players to decide what part they want in that.
Coach tenures are getting shorter, which makes the NHL more of a GMs league.