There's a level of permission they give themselves when they've accepted this kind of nihilism.
"It's all over and there's no God, so what's a little _____ (crime against nature/children/etc.)?"
When in fact every big change in the universe has started small.
It reminds me of religious "the end of the world is coming and we're gonna make it happen" types. Really does eliminate a lot of need for thinking about ramifications of your actions.
A lot of these techbros are involved with the "rationalist" movement, who literally came up with Roko's Basilisk; the idea that a future super-AI is going to happen and would definitely punish you for not making it happen.
ie "What if a boot so big we have to start licking it now?"