The roof of the Sistine Chapel is stunningly beautiful and has much intrinsic value. It also serves to keep the rain out of the church.I have the same feeling towards the "ecosystem services" approach. The more practical values of threatened ecosystems pale in comparison with their aesthetic and intellectual values. However, the latter values do not feature prominently in the "ecosystem services" literature because, in the words of Walter V. Reid, they have so far proved "manifestly insufficient" to advance the conservation agenda.
My disagreement with McCauley stems from his use of the concept of intrinsic value. The Sistine Chapel has aesthetic, intellectual, and other values. They are finite and they are not intrinsic. People enjoy the beauty, or even the mere existence, of the Chapel. That joy is finite. Many people want to preserve the Chapel, but not at any cost. The same with threatened ecosystems.