I never stated that it disables WSH automatically.
I never stated nor implied that you stated such a thing.
One preventive measure that you can take to protect yourself from viruses that come as .vbs attachments is to disable or uninstall the Windows Scripting Host.
Finally, we're getting somewhere. What Norton states is that .vbs attachments can be dangerous. This is not a "strange belief", .vbs attachments are indeed responsible for the spreading of viruses. Clearly, a way to stop .vbs files from being run (or ask the user with big red exclamation marks about it) is needed. The simplest, but most naive, method is to uninstall WSH. What - it seems - you didn't realize is that there are ways to stop .vbs files from being run other than uninstalling (or completely disabling - note the bold) WSH. Norton AV does that very well: it prevents (or asks the user whether it should, something that's configurable) scripts from being run, nothing more, nothing less. This means that no .vbs, .js etc files can be run, but the COM interface of the WSH objects still works. THAT's what mirc uses in $regread/$regwrite/$windir: it communicates with the objects via COM, it doesn't run any script files. So, no running scripts = everybody's happy (mirc, Norton and the user).