A - But NEVER are 5 players at fault, yet all of them get marked as such.
Usually is a combination of failed attempts to maintain and regain puck possession and can be traced to a lot more than a few players sometimes even all 5. I have no idea what base you have for this claim.
B - BS. Goal scoring is a direct result of 1 - 2 players - you can make an argument for 3. Most people today even have trouble with secondary assists as they are. Again, ALL 5 are rewarded for goals scored for.
All 5 usually have had a hand in maintaining or regaining puck possession and zone-entry. They should be rewarded.
It really makes no sense especially when you compared vastly different quality of teams, opponents and situations.
Which is why it is useful to compare players +/- on the same team knowing they have the same environment.
Clarke Macarthur +2
Phil Kessel -10 (scored way more too!)
A - No one is saying has nothing to do with the players on the ice. They are saying it doesn't have to do with EVERYONE on the ice.
Sometimes yes, sometimes no.
B - No, not logically. Perhaps by a stat that doesn't make too much sense for all the reasons I've stated and others have stated.
Very large holes in this dismissal of +/- which of course are easily pointed out. There's lots +/- can tell you. There's things +/- can't tell you.
I'd be a fool to completely neglect the stat.
But then again, I don't really need a stat to tell me Bozak/Kessel/Lupul are very poor defensively, especially compared to the other lines.
Let's use some critical thinking here. Here is also a list of players that according to YOU are major contributors to their teams lack of defensive play.
Martin St. Louis
Taylor Hall
RNH
Alexander Ovechkin
Corey Perry
Ryan Getzlaf
Jerome Iginla
...
Incorrect, because I can put some context behind a +/- .
Kessel's line was the worst defensive top line in the NHL and that's just an indisputable fact.
Most casual hockey fans note that Kessel is the worst defensive player on that line.
Therefore, Kessel is the worst defensive forward in the league.
Simple logic.