I know that Plus is probably more geek-oriented than other social networks, but the fact that the NHL playoffs don't really seem to be "trending" in any meaningful way is kinda ridiculous. It probably doesn't help that most of the NHL teams that have a social media presence have that presence almost exclusively on Twitter and/or Facebook (and, seems, most frequently, FaceBook by way connecting their official FB account to their Twitter account).
But why is it that entitities like the NHL concentrate their efforts almost exclusively on sites like Twitter and/or FaceBook? For starters, FaceBook, Twitter and other networks make it dead-easy to post once and get your message out to a number of sites at once. Google's Plus? Not so much. Crap like this is why Google really needs to work on their cross-platform sharing APIs (have they even published anything meaningful, yet??).
For me, this lack of being able to see updates via Plus is the second biggest reason (behind friends' not being willing to move off FB) that I still need to log into FB and/or Twitter. I come to Plus because I want to. I have absolutely nothing I could (correctly or incorrectly) conflate with a need to login to Plus.