Tough for any team to get much love in LA with the Lakers and Dodgers already in town. You can call it fair weather fans or whatever, other than the Lakers and Dodgers LA does not support teams that don't deliver. Even with the Lakers, seats were much easier to get during down times or when there was no superstar drawing power. I guess LA is not a hardcore sports town like NYC or Philly where fans support inferior franchises and have learned to accept and actually cheer for mediocrity. Just check out a Clippers game, you pretty much get your own row of seats at most home games.
I think an NFL franchise would have immediate success in LA but the support would fade fast if they don't start having winnig and playoff bound seasons.
Regarding NYC and Philly fans, you can't have much of an affect by booing at your TV set at home. Have to be at the games to do that right. Regarding EC fans compared to WC fans - if you are there, watching the game in ANY EC venue, you had better be prepared to be loud and raucous for the home team or explain why you are taking a seat from someone who would.
LA fans? I actually saw a guy apologize for spilling his latte on the head of the "film producer" sitting in front of him. Then offered to buy him a new toupee. Which the fool turned down. If that had happened in Philly, both guys would need new toupees whether they previous did, or not.
Los Angeles is truly a city that has no need for any sports. I doubt they would even notice if the Lakers left town. Jack would just go down to the 'hood and watch a pick-up game.