In the same vein, one could claim use of humans to write code was a mistake. After all, the project failed, this means they made a mistake, so obviously they should have used trained hamsters instead. Do you see where your logic failed you?

> "Using Windows was a mistake" is a truism.

No. No, it is not.

> Failure is regularly equated with having made mistakes.

And what mistake did Windows make here? Keep the baseless insults inside your head, please.

> "Using Windows was a mistake" is a truism

If you use or have used StackOverflow or Newegg, realize that you too are using Windows. Projects' success and failure is much more correlated with the folks running them than the technologies they use.