ETA: I wonder how much he'd be edited these days. Judging by the big fat stuff I see/try to read on the shelves, not all that much?
From what I know about Tolkien, I get the feeling he would be an unpublishable author today. It takes LOTR nearly 100 pages to
start, the story is preceded by a general history of the hobbits and the river-folk, which doesn't really
hook you, and the pacing is practically non-existent, especially in
Two Towers and
Return of the King, where the two stories are not even interlaced together, but told utterly seperately (to get through this, I've found alternating chapters works well).
In point of fact, LOTR violates nearly every rule we learn for getting published. So thank god he was born when he was, because I love the books.
Also, he would have been unpublished because he refused to be edited. You just didn't edit Tolkien - Tolkien edited you (I recall his editor saying that Tolkien would send the editors hand-written comments back themselves edited).
To answer the OP: his style is amazing, melodic, almost a form of prose-poetry, and I think the reason is that he had suffused himself in the world of epic poetry. Yeah, he was a linguist, but he had
breathed so long in these forms of thinking that their common expressions shaped the way he thought.
Nearly the best argument I can find for making your kids suffer through a classical education!