A harsh world it will be, whoredom rampant,The Völuspá
An axe-age, a sword-age, shields shattered,
A wind-age, a wolf-age before man's age tumbles down.
That sounds familiar:
Forth, and fear no darkness! Arise! Arise, Riders of Theoden! Spears shall be shaken, shields shall be splintered! A sword day... a red day... ere the sun rises!(from 3:45)
Hold your ground, hold your ground! Sons of Gondor, of Rohan, my brothers! I see in your eyes the same fear that would take the heart of me. A day may come when the courage of men fails, when we forsake our friends and break all bonds of fellowship, but it is not this day. An hour of woes and shattered shields, when the age of men comes crashing down! But it is not this day! This day we fight! By all that you hold dear on this good Earth, I bid you stand, Men of the West!
(quotes from IMDb. I'd always heard it as "An hour of wolves and shattered shields", but that's just me, and the whole thing with Wargs and also Fenris)
I think we can all be sure that Tolkien was familiar with the Völuspá. So why did he leave the bit about whoredom rampant out of The Lord of the Rings?