A counter argument would be that this is moot. You should secure your systems from these kinds of attacks. To assume that the Iranians or anyone else would not have developed them independently from the Western intelligence agencies is security through obscurity.
In some ways, perhaps Stuxnet did the world a favor, but showing the vulnerability of airgapped infrastructure that people assume is safe from attack. Stuxnet may have accelerated the capabilities of adversaries, but sooner or later, it would have been developed anyway.
By that logic everything that's possible is also inevitable. The feasibility of something is only one factor and, more often than not, new developments are extensions of older developments.
Do you think that the exploits that Stuxnet took advantage of would not have been discovered or leveraged by Russian, Chinese, or other hackers?
I would argue that if your system has a flaw, and the threat model is such that it's feasible for an entity with the resources of a nation state to take advantage of and the value of penetration is high, sooner or later, it will be taken advantage of.
So yes, in that sense, it is inevitable. There's no benefit to closing our eyes and hope that no other state'e NSA equivalent will be able to penetrate our flaws.
I'm not at all in disagreement on your security ethic. It's difficult to say what would happen but context does matter. If Stuxnet came from a different source, had a different target, or was published as a research project the effects would be different. History is ripe with instances where someone makes a discovery, keeps it secret, and it remains secret for a long time so I'm not willing to believe everything is inevitable just yet.
In the final year or two of G. W. Bush's administration, there was an attempt to "run up" to a war with Iran. Israel had a ticking clock on attacking Iran, couldn't let Iran get nuclear weapons, but Israel's ability to bust Iranian bunkers was slowly disappearing. That's apparently why Stuxnet got deployed against Iran, and why Operation Merlin existed. I guess all the hate was about Ahmedinajad, as soon as he left office, the fooforaw died out. This may be evidence that not all the media got the memo that Iran isn't "bad" anymore. Or maybe it's a PR hit in some inter-TLA turf war. The CIA or FBI senses the opportunity to discredit an NSA project, so this appears. Hard to tell any more.
Israel has no capability of taking out the facilities at Natanz with "bunker busters" although just recently the United States upgraded the B2 "stealth" to carry the Massive Earth Penetrator 30,000lb bomb which could destroy those facilities. Besides Iran's facilities are some of the most inspected in the world because they are a member of the Nuclear Non-Proliferation Treaty unlike the few states that haven't signed this treaty such as India, Israel, Pakistan, South Sudan. IMO attacking a country that is trying to develop nuclear weapons while maintaining a massive stockpile of its own is totally fallacious. If Iran were to develop a nuclear weapon it would be only for the purpose of achieving parity at international conventions with nuclear states.
I don't really track the state of Israel's military, I'm just recounting what appeared in the US press at the time. There was some window during which Israel could bomb Iran's facilities effectively. In a few months, that window would close, due to the facilities moving underground or fortifying or something. So Israel had some kind of time running. This was supposed to scare the rest of the US leadership into invading Iran. Thankfully, this never came to pass.
In some ways, perhaps Stuxnet did the world a favor, but showing the vulnerability of airgapped infrastructure that people assume is safe from attack. Stuxnet may have accelerated the capabilities of adversaries, but sooner or later, it would have been developed anyway.