I think you've brought up an interesting point, N. Bookstore are littered with these carbon-copies of Tolkien - and that stuff sells also. Some of it is very good... some of it is like a romance novel with dragons.
Pullman strikes me as very cerebral and high-arty, but it may very well be that the stuff that imititates Tolkien has actually
replaced Tolkien in his mind. Although I do not know how that man thinks. Just total speculation.
I'd ask him if I ever met him, but what if he totally loses it then?