Materialism in Religious Thought

I just read Shaji George Kochuthara's "Conjugal Sexual Pleasure: Contemporary Theological Perspectives" (in Ephrem's Theological Journal 13 (2009), pp. 44-71), a challenging perspective on a thought-provoking, but awkward theme. The author argues that (conjugal –since pre-marriage sex is not discussed) sex cannot be thought of just as for the sake of reproduction. Sex without love would be just an illusory communication and, in fact, be tantamount to a self-erotic act. In this connection, the author quotes a really striking sentence of a Catholic theologian, Dietrich von Hildebrand:

“To regard wedded love as exclusively an objective means to the union of wedlock, and the latter in turn as a means to procreation, would be to subordinate entirely man in quantum homo to man in quantum animal — a thoroughly materialistic view” (D. von Hildebrand, In Defense of Purity, 10-11.).

To me, this view sound ultimately convincing. Still, recently the Catholic Church (to name the one I am more familiar with) has often been upholding this kind of materialistic views on many themes. For instance, one thinks at the stress on the necessity of keeping artificially alive even people who will never regain consciousness (after, e.g., a major car accident) and had previously expressed the desire NOT to be kept alive in similar extreme conditions. Does not this amount to preferring a materialistic identification of (animal or even "vegetal") life as what has anyway to be preserved, independent of its worth as the life of a human person?

Similarly, the stress on the necessity to preserve every single (human) zygote does not seem to regard its spiritual potentiality, but is rather often motivated by the need to safeguard life –understood in a positivistic, materialistic way, that is, as cells and DNA.

I am not saying I do not agree on the content of such actions. I am just disappointed by the materialistic attitude by which they seem to be motivated.