The event was part of the
Crave Festival which the people of Sydney seem to enjoy. We have a similar one here in Brisbane called the River Festival. We don't block off our bridges, but the government does pay for a fantastic fireworks display which I'm betting costs more than the bridge excercise in Sydney.
Most cities do things like this in the name of entertainment or tourism or a bit of both, and let's face it, regardless of whether you think it was a good or bad idea, it's got people all over the world talking about Sydney.
It was a lucky dip. People got to register for the event and then the lucky names were pulled out of a hat, so anyone who wanted to go had an equal chance of being there. Seems pretty fair to me. They didn't have to pay to register. Better than any raffle I've paid to be in. So a lot of people didn't win. Better luck next year maybe.