It shouldn't really be that surprising; there's an awful lot of church music, after all -- it was a very important and greatly admired genre for many many years. (Not so much now, though composers still write masses and requiems every now and then.)

Is that really the link you intended? It seems to go to a performance by Paul Simon of his "American Tune", which doesn't (so far as I can tell) have anything to do with non-Christians liking church music.

Paul Simon does, however, seem to be a non-Christian who likes church music; one of the tracks on Simon and Garfunkel's first album was a version of a Benedictus setting by Orlando di Lasso.