2) It was a back room deal in the sense that it was negotiated in private without input from stakeholders such as city residents.
With respect to your math, the goal of government is not to maximize tax revenue, but to provide benefits for residents. Moreover, even if it was, the proper comparison is to alternative development plans and not to zero. If the goal is to redevelop LIC, why not have a competitive bidding process to redevelop that area? Many companies and developers would be interested and would bid against each other. When you negotiate with one party in secret you lose all your leverage.
I don't understand why any deal is necessary. Google, Facebook, etc. all seem to be doing fine in NYC without special treatment.
This is not about being against Amazon or tech, it is about being again crony capitalism.
--NYC Resident