Windows 3.1 is still being used in the most important networks and systems today

I was really surprised when I read this news from zdnet :
"A Paris airport was forced to shut down earlier this month after a computer running Windows 3.1, a prehistoric operating system from 23 years ago, crashed in bad weather."
But old is not necessary bad as the article says:
 "A few years ago we did a complete analysis of our entire network. Cyber engineers found out that the system is extremely safe and extremely secure on the way it's developed,"

"Those older systems provide us some, I will say, huge safety, when it comes to some cyber issues that we currently have in the world,"


Read the full report on the below given link.