Yes... all of the east-west bridges are that way. The idea is that if you transport a passenger east across a bridge (or north across the GGB) you will eventually, probably need to come back to SF/the peninsula (i.e., to go home). The eastbound passenger gets to pay that expense for you.
Sometimes you get lucky and get a second passenger that is crossing the bridge west/south. Consider that a win when it happens. Doesn't often work out that way. Keep the second toll as appreciation for your hard work. (hehehe)