I really think John Mara has a lot to do with the current trajectory as well as Chris Mara who is head of player personnel. First they screwed up the new stadium royally. It is one of the worst stadiums in the league. But their bad decisions at GM and unwillingness to change their approach as the NFL has changed have really screwed the Giants. Titles matter but they simply have not gotten it done and the current direction is suspect not because of the coaching staff but because of the talent. They kept Reese too long and now are doing the same with Getty. They have had a few wins with personnel, but not nearly as many as they need and have been outsmarted by many other teams in the league. It is that simple.
Agreed wholeheartedly on the personnel issue. Reese inherited a very good roster, with a top notch coach and very good QB. He also aced his first draft, most of whom not only played but were contributors (and, in some cases, significant ones) during that first Pats Super Bowl run. He benefited from all that for a while, with good reason. But a bit too long.
I think nabbing Beckham also helped his longevity. When they made that pick, it was a bit of a surprise with Nicks and Cruz already in the fold (possibly Manningham as well, I forget). Then Odell came out of the box looking like a generational WR, and everyone pointed to that as a huge positive in Reese's drafting.