I think you're missing his point. With Twitter's tax break, they're paying less taxes to the city, and without Twitter's tax break, they'd likely be paying NO taxes to the city (because they were planning to move out of the city). In the near-term, there's no reduction in the city coffers.
>> The payroll-tax break could lead to Twitter saving about $22 million in taxes over six years, the Chronicle said.
I think the gamble was the city would make this back thanks to revitalization or new workers moving into the city. In the near term, there's certainly going to be a reduction in the city coffers for taking care of punchy-guys.