The problem is
humans will remain humans. There will always be ethical and unethical people and the unethical will always find a way around "the law". To say that OS's should be made with limited functionality may be fine and dandy but what about open source Linux, where you can modify and rewrite it any way you choose? Does that mean open source should be banned or creativity chopped off at the knees? What about the hardware - Should it be hard coded to restrict "dangerous" activity? OOPS there goes my FTP to my website. OH yeah, i can get a third party FTP client to bridge a connection. As a matter of fact I can get just about any third party program to do what Windows makes hard for the average user to do.
Do we allow the ISP's to scrutinize every connection we make? Make encryption or proxies illegal? There goes my privacy.
The problem as I see it is that OS's such as Windows has enabled much of what's going on by turning things on by default and having hardware that is "stupid" to what's happening and even measures such as DEP can be circumvented.
So here comes Vista with all it's annoying security dialogs and quirks, making what used to be tolerable.... intolerable and no more secure than previous versions.
So to me it would seem it's the end user who is unfortunately stuck with security since we all want our privacy and freedom. Sandboxing is all fine and well too but what does the average joe deny or allow to write to the disk? Joe needs to be smart enough to decide that unless you want to totally sandbox everything and not allow anything to write to disk.
The virtual world is much like the real world in terms of keeping your privacy and allowing you to do your own thing, as long as it's legal. Then there's things that may be illegal here but legal somewhere else. So I go somewhere else and we all know there are a lot of "somewhere else's".
There certainly isn't any concrete answer to keeping the net alive and well, without the "accidents" or deliberate unwanted actions. Well, there may be one way but do you really care to be completely regulated and controlled?
As in real life, we are all walking or surfing targets and always will be. The best we can do is educate and train people. So maybe a license is the way to go but there will always be some who break the speed laws or drink while they surf or fall asleep behind the wheel.
Besides all that, what will happen to poor M$ if they didn't have anything to do by way of "upgrades" if everyone who surfed with a license had the ability to stave off all the nasties out there?
IT's a cruel world.