Well, I'm not convinced. In fact it would seem that some theologians have more or less the same interpretation:
While the pope never mentioned “homosexuality,” it was his explanation of the nature of man and the order of the natural world that caused gays to react so harshly, Fr. George William Rutler, a leading Catholic theologian, told CNSNews.com.
The pope was saying that man is made in the image of God and is therefore “unique” among all species and has authority over nature, Fr. Rutler told CNSNews.com, adding that realities such as gender – man and woman – are not arbitrary developments in biology, or accidents, but are clearly defined in the natural world for a reason.
If a person rejects nature’s assigning of gender, or tries to change it, then that is disruptive to nature and destructive, said Rutler. The natural environment must be responsibly protected, as the pope mentioned in reference to rain forests, but so must the natural order in men and women, said Rutler.
Ah yes, the classic argument from the clergy - if you are gay or transsexual, it's all your choice and you are "rejecting" God's divine order. I guess that "God's plan" for the world didn't include the Intersexed, or those who are simply infertile for whatever reason either.
This is why homosexuals see the pope’s remarks as threatening, said Rutler. “The homosexual is a classic Gnostic,” he said, “because the homosexual does not understand how gender is intrinsic to God’s will for the human race. Male-ness and female-ness are not arbitrary categories.”
Oh yes, the Pope may well have been speaking in allegorical terms or just plain riddles, but his message was plenty clear enough. Using the "but you don't understand ..." argument doesn't cut it. It's not hard to understand the Church's position. When the line of reasoning being used essentially tells an entire population that they are for one reason or another "immoral", "evil" or "invalid" as people. The message is the same, and it doesn't take much to pick up on it, even when it is carefully concealed in riddles.
The second point is that the "Natural Law" that the RC Church works from does not account for a great deal of the evidence that is available today. (Unsurprising, since Aquinas has been dead for several centuries. Consequently, the understanding of GLBT people as surprisingly ordinary human beings isn't reflected in there. In the following article, a point is made clearly that appropriately raises the kind of problem that the Church's "Natural Law" interpretation faces:
Perito questions both the validity and the reasonability of such an interpretation of natural law. A more person-centered view of human sexuality is explored by Perito. Telling gays that God loved them into existence and treasures them as people and simultaneously telling them that it is wrong to act on their feelings to act and love sexually is inconsistent. To many it appears either that God made us as we are, with all that entails about our sexuality because God loves us, or God has done something rather strange, created natural impulses (for homosexuality is as natural in the animal world as it is notable in human society) in order to frustrate them at every turn.
Convincing gays never to act on their sexuality because an interpretation of natural law theory believes the only purpose of sexuality is procreative, is comparable to telling gays to go play in traffic or to find somewhere to die. There the inherent sexism of this interpretation of natural law is apparent, and it is also socially acceptable heterosexism.
While I view homosexuality as quite distinct from transsexuality, the fact that the leadership of the Catholic Church insists on lumping the two together by using the term gender as a synonym for sex, and thus sexuality, so chances are pretty good that what is said about the GLB applies equally to the T.