I don't have any light to shed on this outside of what anyone may glean from the relevant Letters. Letter # 261 seems IMO particularly telling, in which he defends Lewis' memory in response to certain others who in his opinion didn't know what they were talking about and ignorantly if not maliciously misrepresented Lewis.
Quote:...I wish it could be forbidden that after a great man is dead, little men should scribble over him, who have not and must know they have not sufficient knowledge of his life and character to give them any key to the truth.
.
Maybe Tolkien, in view of the fact that he'd been estranged from Lewis and disliked certain of his works, particularly the Williams-influenced ones, was
recusing himself, if you will, on the grounds he should be disqualified from such commentary on Lewis, lest for those reasons he would fail to do Lewis justice? The Letters do IMO seem to rule out animousity or bitterness.
That's
my take, anyway.
I'll go grab some sleep now, and resume scribbling over dead great men another day. :crown: