It really doesn't. You coulda played really well on a play and the other players on the ice **** the bed but that doesn't matter you still get a -1. What about when a goalie lets in a super soft one? Its too general and too stupid of a stat to be used nowdays
Teams play in units of 5 even more so in today's game so if you're a minus on a regular basis (ZIB -6!!), it's a problem and something can't be ignored..