I have a theory that as people become less religious, they view their limited time on Earth as more precious.
If your religious, a lifetime of toil doesnt really matter when an eternity of bliss awaits. If your not, you realize that every hour spent here is one less hour of your overall existence and therefore why would you spend it in servitude to make someone else wealthy while possibly being treated like a disposable tool.
This is just an idea I was thinking about but wonder if there's anything to it.