My point is that there's no reason to consider yourself safe from blackmail (and the consequences of ignoring it) just because you've adopted a certain precommitment. Other entities have explicit incentives to deny you that safety.

In a multiverse with infinite resources there will be other entities that outweigh such incentives. And yes, this may not be symmetric, but you have absolutely no way to figure out how the asymmetry is inclined. So you ignore this (Pascal's wager).

In more realistic scenarios, where e.g. a bunch of TV evangelists ask you to give them all your money, or otherwise, in 200 years from now, they will hurt you once their organisation creates the Matrix, you obviously do not give them money. Since giving them money would make it more likely for them to actually build the Matrix and hurt you. What you do is label them as terrorists and destroy them.