So here's the thing about the Subban booing and why I think there are "half-truths" in all the arguments here. The booing of star players is a factor yes but when you look at arenas around the league, they don't boo star players as consistently as they do Subban. In Toronto, we don't boo Crosby/Malkin; when I watch say, the Devils - they're not booing Stamkos, etc. It's easy to sit here and say, "oh - he's a star player so he gets boo'd!" but it doesn't happen consistently around the league enough to consider it a sole reason. Half-truth #1.
Now to the above, while I don't see booing star players a consistent thing in the league, its not that fans don't want to boo star players, it's that they don't know who they are when watching the game live. We forget there are MANY casual fans in arenas and while they may know players by name, they won't know numbers and they can't exactly see name plates. This is where the race thing comes into play. A casual fan looks onto the ice and sees a bunch of white dudes with numbers, they don't know when the star player who they want to boo has the puck so they sit quietly. Enter P.K. Subban. Everyone knows him by name, and they know he's a star, and they want to boo him because he is the star. You're playing the Montreal Canadiens and he is the only black player on the ice. Casual fan looks onto the ice and sees the one black player on the ice has the puck - it's obviously P.K. Subban, they don't need a number or nameplate - cue the boos.
tl;dr - it is fans wanting to simply boo star players but the fact that Subban is more recognizable due to him being the only black player on the Habs makes him get booed more often because casual fans in arenas can easily pick him out.
