That's a false dichotomy, because nonreligious people find some other ways to create an "us vs them" mindset. We see it all the time.
It's also a fallacy to group all religions under one banner and claim that they all say the same. Even among what you call "organized religion", while there is some overlap between say Islam and Judaism/Christianity, once you start looking at things deeper, you'll see how Islam comes out different, and as a Muslim, I'd say on top.