And yet the Red Sox, Cubs and Yankees sell out every game and they show up.
The Dodgers, with the exception of last year because of the protest, draw more total fans than the teams you just listed most years and will draw more than most of them this year.
Keep in mind that most stadiums only hold to 30,000 to 40,000+ thousand. If Dodgers stadium was the size of those other stadiums, they too will sell out every game and last nights game would have been almost capacity. And since Dodger stadium seats are brightly colored you will notice the empty seats more so than other stadiums
You also got to realize that the west coast is different. Everything on the west coast occurs much earlier and is much more spread out (particularly LA). This is not an excuse, it is just the reality. People on the west coast go to bed earlier and wake up much earlier so it is much more difficult for them to go to a game that ends at 10pm, take another 2 hours to get home after that, and then have to wake up at 4am or 5am.
Also, people in LA are whimps when it comes to rain.
Unlike other cities, very few people live in downtown LA. Most have to commute anywhere from 30 minutes to 120 minutes to get to downtown LA as most of the population is in West LA, the San Fernando Valley, San Gabriel Valley, Orange County, or the Inland Empire. Even within the LA city limits most live in the San Fernando Valley and it can take them a good 2 hours to get home after the game (It takes over an hour just to get out of the parking lot). So it is very difficult for people to attend midweek night games. When they are playing a team that nobody gives a damn about (like the Pirates), not too many are motivated to go through the hassle of attending the game when it is much easier to stay home and watch it on TV.
If it was an afternoon game, they were playing another team, and/or not midweek, they would have drawn a lot more.
Look, the Dodgers were the first team to draw 3 million and did so for 5 years before any other team, have drawn 3 million fans more often than any other team, are usually #1 in NL attendance, and have drawn more total fans through their history than any team in any sport. They have already sold 3 million tickets this year and the season just started. I will bet you that with the new ownership and if they build an exciting team for next year, they will draw 4 million next year.