Comment by petcat
In a lot of cases, it's the only way that municipalities can submit bids for projects they want. And in the commercial space the bidding process is usually confidential. So it's just basically a requirement of public private partnership.
Of course the municipality could just say that they don't want the project and they won't submit a bid. That's fine too.
Municipalities should not be bidding on corporate benefaction; this is exactly the opposite of how the relationship between the public and private sector should be.