Just a little nit-pick. I agree with the gist of what you're saying here (and like your bit about the cynicism of Gen-X), but I don't think even applicability was Tolkien's intent, he just somewhat famously disliked allegory and was resistant to allegorical interpretations of his work.
I think his stance was more, "If you want to apply it to some kind of meaning, great, but I'm just trying to write a good story." Or rather, he was deeply immersed in bringing Middle-earth to life, and his books were a way of both exploring Middle-earth and sharing what he "discovered." Obviously his life--and perhaps especially his experiences of the two world wars, and the overall impact of industrialization in England--were deeply impactful. But he didn't like the crudeness of saying, "the One Ring is nuclear power" or "Sauron = Hitler" or "Mordor = the industrialized Midlands."
One of the great struggles of his life was his inability to publish what would later become the Silmarillion. When his publishers asked for a sequel to the Hobbit, he showed them bits of the Silmarillion and they said, "Uh, very interesting, but can you give us a story about hobbits and not a bible on the elves?" Thus LotR. Even up to the point of its publication in 1954-55, he tried to fold the Silmarillion in as a package deal, but Allen & Unwin were hesitant, and he even talked with a different publisher, but they wanted to heavily edit LotR, so he went back to Allen & Unwin.
But my point is that what he cared about, more than anything, was the Silmarillion - and the entire creation of Middle-earth. I imagine that if he were a more prolific writer, and/or he lived a lot longer, we would have seen novels written about about earlier periods in Middle-earth's history, fleshing out segments of the Silmarillion. To him it was a living, breathing secondary world - an imaginary world that was true in its own way. So whether we're talking about allegory or even deeper meanings that can be read in the text and applied to stuff in the real world, Tolkien's focus was on the world itself.
That said, he did discuss some of the meanings he saw in his creation, but it was more in an "after the fact" sort of way. Meaning, he wasn't trying to make a point in the guise of a fiction story, even in an open-ended way (applicability). He was approaching Middle-earth as a living reality, and expressing what he discovered in his writings. In a way, any deeper meanings he saw in the text were seen after the fact - he would write and create, and then reflect upon what he came up with.