It is therefore rather irresponsible of the scientific community to allow such a bad state of code technical debt to live on for so long, when it’s dealing with a field that is inherently tied to the study of life-or-death scenarios (like we are facing right now).
The only way to avoid this inevitable conclusion of irresponsibility would be if the scientists behind the model warned that it cannot be trusted at all due to the potential of a large number of unknown bugs (did they?). Otherwise, either the scientists are irresponsibility incapable of understanding how to write reliable complex code, or were not honest about the trustworthiness of their code.
If there is ever an asteroid heading towards the earth, I swear that some segment of HN will write angry articles about how the hastily built nuclear-powered spaceship we sent to intercept it doesn't have proper unit tests. They'll demand that we delay the launch until 300 days after impact.
We knew this was coming for months. The code isn't that large, it's just horribly written. If the scientists had worked in collaboration with an expert team of technical programmers, they could have handed off their mathematical models and had a well implemented, extensively verified program to run those models within a useful timeframe.
That might sound extreme, but once again, I will reiterate that expert advice apparently based in part on the output from this program is being used to inform decisions that will affect whether thousands live or die and that are severely curtailing the normal lives of the entire population with other adverse consequences that nobody fully understands yet. Powerful responses require powerful justifications.
If you look at the original article, you'll note that for at least a month the code has been receiving attention and refactoring from a team at Microsoft. Your criticism is that an academic team should have somehow convinced Microsoft to donate these resources before the epidemic became severe.
I'm going to go way out on the thinnest limb and propose that major software companies were not chomping at the bit to donate resources to epidemic modeling teams until very recently, and this isn't the fault of the epidemic modeling teams -- as much as you seem to think it is.
I'm also curious about why they brought in the people they did to do whatever cleaning up was done before publishing this code. There are several businesses in the UK that do this kind of work as a major part of their activity in one way or another. Current or former staff with that sort of background would have been the obvious people to tap for assistance. To the best of my knowledge, the people who have actually been identified as having helped have no such specialist background.