Why is Tolkien not an 'Anglo-Saxon'?

So, here I am back in Milwaukee for another research trip. But first I wanted to post about a curious passage I came across when reading THE FALL OF GONDOLIN last week (book #II.3500 on the reading list, for those who are keeping count).

The line that caught my eye was Tolkien stating, in a letter to Stanley Unwin,

Unfortunately I am not an Anglo-Saxon
The context in this 1951 letter is Tolkien's recalling the outside reader's report rejecting THE SILMARILLION fourteen years earlier, in which the reader 'allowed it a kind of Celtic beauty intolerable to Anglo-Saxons in large doses'

But why shd Tolkien preface his comments about THE SILMARILLION's refusal to be suppressed with the comment about not being Anglo-Saxon?

Is Tolkien being ironic, along the lines of 'if Anglo-Saxons don't like this kind of stuff, and I do, then I must not be one of them'? I know Tolkien in some times and moods described himself as a Hwicce, but that doesn't seem apropos in this case. Indeed I wd have thought JRRT had a better claim to calling himself an 'Anglo-Saxon' than many, being of Saxon ancestry on the Tolkien side and Anglish descent through the Suffields.

In any case, one of Tolkien's more oblique statements, I thought.

--John R.

current music: THE WHO'S TOMMY (esp. the second half)
current reading: BEREN & LUTHIEN, some Japanese light novels.