I'm wondering why do you think this is true? Using stuxnet as an example, would it not be better if they used every feature within reason that would add to the likelihood of success? Why does reductive elegance make an application of technology superior to an inelegant solution? Does final effectiveness not overrule the developer's aesthetics?

I'm asking in honesty, not using the question to merely attack your opinion. I recognize there are things I have probably not considered.

Referring back to my natural gas pipeline example, just install the nasty centrifuge control software at the factory.

It is easier and more likely to succeed. Also, stuxnet has now been repurposed by multiple governments and criminal organizations. So, it’s creators built a symmetric capability, and gave it to their adversaries, when they could have used asymmetric capabilities that are more expensive to reproduce.

[edit: Also, it is still well within the Iranians’ capabilities to build a bomb, and our recent foreign policy greatly increases the chances that hard liners will take over and restart the program.

Contrast this to the outcome of the broader cold world strategy, which was a regime change to a relatively US-friendly government.]

Irreducible complexity sounds like an incredibly high bar.