I disagree. We have all of the building blocks to make a truly secure language/operating system. I actually hope the rise in popularity of crypto-currencies will spur investment in new operating systems that address these problems. Windows, Unix, and OSX are all based on 40+ year old technology. It's the huge amount of infrastructure and investment built around these old OSes that is holding back progress. Not only is a secure operating system (one free from viruses, malware and the like) possible to build, it's not even terribly difficult (but it will take a lot of effort and require a large amount of investment that might require many years to recoup).
I'm in love.
I've been making that argument to people for a good twenty years. And the same applies to computers themselves in a lot of ways, honestly. The notion of how the building blocks of a machine interconnect, for example, that's been almost a constant. Minor improvements here and there. Never any complete rethinking of how stuff works.
Starting over as close to possible as from scratch would indeed require a lot of effort and investment but it's one of those things that if it works... would just change everything. And pay accordingly.