Gaming

I don't think they (the cultists) were right.

I kind of like the ending because I actually think it's a bit open to interpretation.

You play as a county deputy alongside the sheriff and other deputies. Throughout the game, it's alluded to that the feds are already aware of the situation and will eventually be alerted and intervene, especially when it's found out that local enforcement was killed/kidnapped/unable to execute this warrant. The cult puts a substantial amount of effort into maintaining radio silence and preventing people and information from leaving Hope County.

I think that the ending is simply federal agents learning the situation is fucked and choosing to bomb Hope County in order to contain and destroy the cult. It's not a nuclear Holocaust like the cult prophesized.

You do see a mushroom cloud in the ending, but a nuclear bomb isn't something that you look at, panic about, and successfully drive away from (as is what happens in the ending). I think this bombing was caused by the cult's actions. In a fucked up way, they brought about the Armageddon they foretold. One that wouldn't have existed without the cult.

It's still a sad ending as everyone dies and the protagonist is captured again, but I think it underlines that Joseph Seed can frame any event (such as literally his whole cult dying) as an affirmation of his beliefs.