Two years ago, the same developer was working on an even older system with BASIC… Which I guess they already retired.
But if you've got an OS that's certified for the work you're doing, and it's not costing you extra to work on that OS, then there's no fallacy - you're getting more value out of the cost of certification you've incurred, and shifting to some other OS would presumably require you to incur the expense of certification again.
That said, the skills needed to work with a legacy OS will tend to become rarer, so you ought to factor that into your calculations.
aversion to real costs is not a fallacy.
I'm guessing that in this example, it was more expensive to switch to Linux and recertify. I doubt anyone in management was really arguing against a cheaper option because of money spent 10 years ago.
And than you bet on the wrong ditro. I do support work for a commercial Linux Desktop program. We went from SuSE, to CentOS, to Scientific Linux, to Ubuntu. Lets hop Ubuntu stays. :-) Our "luck" is every five years or so we exchange the machines.
They used 30 years the same Windows version. So maybe they can use 30 years the same Linux version. I don't know. All I know is, choosing Linux is the opposite of choosing stability.
I would argue that a close-source (at least before the leak), non-supported kernel is way more unstable and risky than an open-source, still maintained one (some kernels are actively maintained through 2033).
Bear in mind that the position was not about developing/maintaining the OS, but the applications that run on it.
Is it a fallacy if the cost is specific and enumerable?
That with the scandal sounds interesting, so you have any pointers where I can get a good sum-up? :)