F2Pool already knows that having their blocks rejected by a bunch of non-economic nodes will have exactly zero effect upon their business.
That only works if all the mining pools agree not to adopt the BIP. If even one of the pools signals or thinks that another pool is about to signal, the prisoners dilemma plays out. Everyone will be watching. I know the CORE 30 supporters say it won’t happen, but I know they are worried that someone will flinch and flip to signal for the BIP.