You just made my point for me. You admit the system (in your opinion lack of) is the problem. You admit the Coach and GM is the problem. Then you go right back to blaming Leddy.
The system, or lack thereof, is a TEAM problem, yes - but when watching Leddy not hustle, not tie his guy up in front of the net allowing 2, 3 or 4 whacks at the puck before taking action, never being physical to close off an on-rushing attack, etc., one can see it doesn't matter what system is or is not in place - he is playing lazily/poorly, and the +/- is reflective of that.
The two issues - lack of good coaching/bad defensive system and passengers not playing hard or hustling - are not completely mutually exclusive, but can be distinctly separated, and in Leddy's case, most of his poor play this season has not been driven by the team's defensive system. IMO, if he was inserted into the 2009 Bruins defensive corps he'd still have a bad goals against.