My entire point is that Amazon has likely already chosen its HQ2 location for unrelated business reasons. But if the finalist cities think that it has not made

My entire point is that Amazon has likely already chosen its HQ2 location for unrelated business reasons. But if the finalist cities think that it has not made up its mind yet, and that tax incentives are the primary criterion it is using to make up its mind, then Amazon benefits from them thinking that. It still gets the HQ2 in the city it wants, but on top of that it gets highly competitive tax incentives. It's not going to chose that place in Idaho (or in my tiny state of Delaware, which also made a proposal) just to spite them.