People use 20 years in the future todays common hardware and software as a mission critical platform because they have software system build on top of it. And when they finally have to upgrade there is going to be compatibility problems, that where not expected.
Software needs forward compatibility build in it because management isn't going to believe there are problems until there is real hurry to fix it TODAY, when last part was made over decade ago and there is nothing compatible has been available for years.
And things get worse because systems made today are far more complex and used in ways that they where never designed for.

I would add that over enthusiasm about "internet of things" seems to be in industrial management professors, which pretty much means future management is trained to believe that every machine in factory needs to be connected to internet and have intelligence in it.

Next time you hack together a quick script, just think about the poor factory worker whose limb maybe dependent your script working correctly on operating system distribution that will be made 20 years after you made your script, and there is definitely no guarantees that the dependencies work same way as they worked when you made the script. And the guy who integrated your script to a factory machine just ran couple tests with it and tried no exceptional inputs.