Could it be that ADA failed precisely because the government mandated it and then failed to adhere to the mandate?
One analogy is smartcard technology. This technology has been in use in France for almost thirty years. It is now an embedded part of their national phone system, and people use smartcards instead of checks for most purchases.
Yet this technology has had lukewarm reception in most other countries. I think the major reason is the French government mandated the use of the cards (it was a French invention) and made good on the mandate.
Had the US government done the same, ADA might be a rousing success. But then if it was so good, how come it failed the ultimate test — the marketplace.
People complain (and have complained) for years about the various flavors of Windows, and its predecessor MS-DOS. Yet the Windows family of OS is the king of the hill. Practically created the PC industry (at least according to some). Yet no one would use it to program anything requiring a system that was failure resistant. We have a machine in my company that will reliably go to Blue Screen after two days, even though nothing is running except Windows. If the OS is that unstable, how good can it be when it runs an application?
The software industry has been dealing with productivity and delivering good systems on-time for lo these many years. As a 20-year-plus veteran of code wars, I've seen development models and ideas come and go (chief programmer teams, structured methods, etc.), and every year another one comes out of the woodwork.
I would prefer a pessimistic person, dedicated to producing a good product, and thinking about the overall job to be done, than a couple of dozen people all trained on the latest gimmick.
Because one person who cares about his work is worth more than the rest of them put together.