LA for sure the drop in basketball attendance isn't confined to UM, AWF mentioned that in an earlier post. As far as the video game/smart phone thing, that is really kind of a weak excuse. In the 70's there was video games (sure you had to go to an arcade), Pong, ping pong, foosball, bowling, movies and just as many other distractions and alternatives for kids to do. And there has always been parties, although in fairness in the '70s and early 80's after the game the students could go over to the TPS or The Library or Stocks after the game and didn't need to find a party at 10:00pm after the game to have a few libations, so that has changed.
Maybe we are going about this all wrong. Maybe we need to take a good hard look at UM basketball demographics, and change our expectations. Maybe instead of being a loud, screaming mass to be be intimidating we need to adopt the opposite - the fans just sit there, lean back in their chairs with arms folded and give the old probation officer stare to intimidate the other team. No cheerleaders, no band, no rock music on the pa, no flashing "NOISE!!!!" signs, no Monster Truck PA announcer, just a bunch a stern old guys staring right through the bullshit without saying a word. Hey it would be unique, maybe even trendy, and God knows that is all it really takes to draw a crowd, just be trendy. no matter how dumb.