> Mordor makes one think of trenches and devilish factories.
Tolkien hates you now!
But seriously, he was open about how WWI influenced his writing. I think his rant against allegories is more about direct allegorical reading like "Mordor is supposed to symbolize WWI trenches etc."
I totally agree here. I think there's a difference between recognizing where Tolkien's inspiration came from vs saying that an element which took inspiration from elsewhere was necessarily meant to specifically represent that thing in his work.
Both because he was in it and because it was the first industrialised war. Mordor makes one think of trenches and devilish factories.