Thirty-five years ago, cultural critic Ellen Willis wrote, "it is depressing to have to insist that sex is not an unnecessary, morally dubious self-indulgence but a basic human need, no less for women than for men".

If it was depressing in 1979, it looks downright miserable today.

Because let's be clear: While Monday's US supreme court ruling in favor of Hobby Lobby was officially about religious freedom, the real issue at stake is sex – namely, if women should be able to have it as freely as men.

The court ruled – in a 5-4 decision in which all the female justices dissented – that a closely-held company does not have to cover contraception under the Affordable Care Act. Hobby Lobby argued that, as a corporation, it has religious objections to certain forms of contraception that it believes are "abortifacients" (they are not). But the underlying values that drove this company to sue – and spurred a national debate – is the belief that women having pre-marital or non-procreative sex is wrong.

There is a reason that the first large-scale cultural reaction to the issue of insurance coverage for birth control was a female law student being called a "slut". Sandra Fluke's testimony to a congressional committee in favor of contraceptive coverage for a friend's serious medical condition set off an apoplectic frenzy of sexually-based attacks on her – and they weren't just limited to pundit Rush Limbaugh calling her a "slut" and "prostitute" on the air. (Even today, I still see tweets calling her a "whore".)

More than 30 years after women thought the right to birth control was fought and won, we are still having to justify why we'd like to have sex – and why that doesn't make us bad, immoral or disgusting people.

The true concerns of conservative "freedom-seekers" are made especially clear in the amicus briefs in support of Hobby Lobby – which sound more like abstinence-only education curricula than legal arguments.

One brief from the Beverly Lahaye Institute and Janice Crouse (who once gave a sex talk to college students called "False Promises, Searing Pain, Tragic Problems") insists that the court consider the "documented negative effects the widespread availability of contraceptives has on women's ability to enter into and maintain desired marital relationships". The American Freedom Center argued that birth control has "harmed women physically, emotionally, morally, and spiritually". And lawyer David Boyle wrote in his brief that contraceptives are not necessary, "since sexual relations are basically a voluntary activity. ... [S]ex is only a human want (like bowling or stamp collecting), not an actual need".

Bowling or stamp collecting. The jokes write themselves.

Legal decisions about contraception have always been based, at least in part, on concerns about women's potential promiscuity. The supreme court decision in Eisenstadt v Baird that gave unmarried Americans the right to procure birth control – in, yes, 1972 – was sparked by the arrest of William Baird after he handed a condom to an unmarried woman at a lecture he was giving about birth control at Boston University. At the time, his action violated Massachusetts law on "crimes against chastity".

Decades later, we've seen the conservative obsession with women's sexual purity restrict access to Plan B and the HPV vaccine – and now it's interfering with women's access to health care, of which sexual health is certainly a part.

Dr Nancy L Stanwood, the chair of the board at Physicians for Reproductive Health, released a statement on Monday saying that "[c]ontraception is essential to women's health and well-being, a critical component of preventive care, and integral to the health of families."

The court put to rest the slippery slope concern many had, stating that the their decision "concerns only the contraceptive mandate" and not vaccinations or blood transfusions. But Louise Melling, the deputy legal director of the American Civil Liberties Union, noted in a call after the ruling that this exceptionalism only seems to apply when it comes to women and reproductive rights - or, as lawyer and writer Jill Filipovic tweeted, "Whew, really glad #SCOTUS made sure its #HobbyLobby decision wouldn't negatively impact men who need medical care some religions object to!".

And while SCOTUSblog reported that the decision will allow for the government to "provide alternative ways [for women] to obtain or access [contraception] coverage", several women's health leaders I heard from said that is far from certain.

No matter the legal rhetoric, the message about women and sex remains the same. It seems appropriate that that quote from Ellen Willis is from the essay "Abortion: Is a Woman a Person?" Because what's at stake in a decision like this – and in a debate like this – is women's basic humanity, of which sexuality is an integral part. Yes, contraception is about health and women often need birth control for medical reasons – but we also need it for sex, and that's just fine.

The supreme court wrote that this decision doesn't "provide a shield for employers who might cloak illegal discrimination as a religious practice". But what else can we call the targeting of contraception - and the targeting of women's health and lives?

READ MORE ON HOBBY LOBBY:

• Hobby Lobby ruling: Firms can refuse to provide contraception coverage

• Gallery: Reactions to the supreme court's ruling on corporation's religious rights

• Plus: Supporters and detractors react, from Washington and beyond

• You told us: Me and my affordable birth control

• Earlier: What Sandra Fluke knows about Hobby Lobby