We're not talking about ensuring the system operates in a normal expected environment though. It's not exactly complicated to make sure your software doesn't kill someone. What WE ARE talking about is making that elevator software completely impervious to any attacks or any kind of bypassing of the controls to ensure no one is killed.
Holding a software programmer liable for all potential flaws in their code is rather ridiculous and shows a general misunderstanding of how software is written. We do not just go out and build a bridge. We go out and purchase or use countless components that are prefabbed (libraries) and we build the bridge in methods suggested by industry standards, programming language standards, or vendor apis. When you purchase or use any software by anyone you are not just using software by them you are using software and programming techniques designed by countless other companies. There are so many interdependencies it is insane.
Let's be honest. The only reason why anyone is for this is because they are sick and tired of Microsoft and companies like them that are interested in their bottom line first. But most software companies wouldn't exist today if every line of code had to be iron clad and secure from bottom to top. So if we go the route this article is suggesting we are going to have software companies with no IP owned by just that company (open source distribution so the purchaser can make changes themself) or we are going to have very short lived software companies that are sued bankrupt every day they hire an outside contractor to do job xyz.
This entire concept is a joke. The problem with software security does not rest with the programmer or the organization. An entire industry would have to change over night to support anything even remotely like this.