Its his responsibility to make sure the draft picks develop. The draft is a crapshoot yes, but if you miss one top ten pick that is bound to happen but miss on both is an issue. On top of that, he gave away picks the next few years, so the team being bereft of talent is on him. Fleury might have had issues but the man still put up almost 70 points for us.
1999–00 New York Rangers 80 15 49 64 68
2000–01 New York Rangers 62 30 44 74 122
2001–02 New York Rangers 82 24 39 63 216
When he did keep his draft picks he whiffed badly. So the talent drain was on him. As for the team aging, you're absolutely right. The teams average age was up there, but who brought back Messier in his first season, and kept the team old by getting guys like Kaspirits and Holik. He also inherited plenty of youth in guys like Malholtra, Jonson, York, and Hlavac who had decent years which you are overlooking.
Again, the only reason the team bounced back in my opinion is because of Don Maloney. he let the guy do his as the VP of Player Personnel and it paid off. Maloney deserves more credit for our turnaround then Sather. For every Jagr Sather had a Lindros, Carter, and Bure. I am not counting Nash and St. Louis yet because I want to see what they can do during the tenure of their Rangers Career. For every Lundqvist (which he got extremely lucky on), he had a Blackburn and Montoya. I really do think people are letting this stanley cup visit cloud them on the totality of the man's accomplishments here. For every Kreider he had a Jessiman. I am trying to think of a free agent signing the man had that was decent to make a comparable but I am genuinely drawing a blank.