Not sure it is a good saying. Brett Devereaux covers it in detail in his "fremen mirage" articles which I find a good read.
https://acoup.blog/2020/01/17/collections-the-fremen-mirage-...
https://acoup.blog/2020/01/17/collections-the-fremen-mirage-...
> Second: Consequently, people from these less settled societies are better fighters and more militarily capable than their settled or wealthier neighboring societies.
> Third: That, consequently the poorer, harder people will inevitably overrun and subjugate the richer, more prosperous communities around them.
I prefer real history to science fiction, myself. The 30s were indisputably hard times, but they produced the people who won WW II and went to the moon.