As with every team in the big leagues now, the higher end seats (lower bowl, courtside, 50 yd line) are the big money seats. Owned by big money people. They may or may not show up for every game, but the seat is still sold. By the numbers it is a sell out, by the butts in the seats, they are a few thousand off. It does look bad on tv to see the empty seats, but they are all still paid for. Announced attendance, done by ticket sales, and actual attendance are often quite far off.
I'd be going to several games a year if I didn't live like 4.5 hours away.
Going to a game is like an adventure, and it's costly when you factor in the time, gas, and lodgings. Not to mention the beer and food.