That's so much crap it's not even funny anymore. As you can see from several above posts, Microsoft charges for their crap OS and then you have spend time and money to keep from getting drowned in viruses and trojans.
I'd agree with you that just about any version of VMS can be a robust and secure system. Not nearly enough userland software for it that I'm aware of though.
As I've said upthread — what we really want is a formally verified OS. There are technical reasons why any Unix/Linux verification would be prohibitive, mostly due to the time/effort of verifying C-style languages combined with the complexity of an OS — formal verification isn't something you can just bolt on, so most extant OSes can't realistically be verified simply due to the complexity constraint alone. (There are several languages that would actually help in such an effort to verify an OS: LISP, Eiffel, and Ada spring immediately to mind.)*
I'd agree with you that just about any version of VMS can be a robust and secure system. Not nearly enough userland software for it that I'm aware of though.
That's the biggest downside to VMS that I know if — much like Ada it tends to have fallen into its own niche, in Ada's case it could be a blessing because it already has a reputation for reliable and safety-critical programming… and that seems to be a trend that is/will-be as security is compromised by forces foreign and domestic, official and non. — the only reason I don't have a VMS box is because I don't have the monies for it. (But if I had a web-based business I'd definitely find the monies to move to VMS and Ada.)
* —
maintainabilityas a design-goal. Given its gearing toward interfaces/contracts, it would make for an easier time of proving.