Why do they care? The obvious answer is: money.The amounts being spent to advertise and advance this lifestyle choice seem vast until you compare it to the amounts that would be spent by a society that invests in a lifetime of additional medical supplies and treatments. If even an extra few percent could be convinced to do it, purveyors of such technologies would make back their investments many times over.
Melding this manufactured medical issue with civil rights frame entails the continuance and growth of the problem. Transgenderism is framed as both a medical problem, for the gender dysphoria of children who need puberty blockers and are being groomed for a lifetime of medicalization, and as a brave and original lifestyle choice for adults. Martine Rothblatt suggests we are all transhuman, that changing our bodies by removing healthy tissue and organs and ingesting cross-sex hormones over the course of a lifetime can be likened to wearing make-up, dying our hair, or getting a tattoo. If we are all transhuman, expressing that could be a never-ending saga of body-related consumerism.
To a certain degree technological change makes these kinds of things likely. William Gibson was imagining cyber and biotech allowing people to alter their bodies decades ago; one gang he envisioned replaced their teeth with animal fang implants. We will be in charge in a new way, and that means we can treat the body as an opportunity for a kind of art.
Against that challenge, of course, stands the Aristotelian philosophy we've been discussing. Because it sees nature as the source of the good, it will be predisposed to reject adopting a lifetime of pharmacology to suppress hormones or provide humans with wolf-like teeth. The role of art, for Aristotle, is to perfect the goods inherent in nature but imperfectly or incompletely realized. Dental surgery to fix improperly-grown teeth is good because it improves the perfection of a natural good; pulling out the teeth and replacing them with wolvish fangs that do not fit the natural diet of a human being is bad because it works against rather than with the goods of nature.
"Well, we can change our dietary tract too, someday, at least in principle; and we can grow 'meat' in vats that will avoid any ethical problems with switching to an all-meat diet; and we can force, with drugs and surgery, our bodies to accept all this, becoming artists of ourselves."
Perhaps. But there is something to be said for being able to sleep under the stars, with no medicine and no technology, to survive on natural strength rather than technological infrastructure. Aristotle has an advantage here, even in spite of all the long years and great changes.

