It was a dumb idea to use http:// as the namespace for XML DTDs. They should have used URIs that don't work when typed into a browser, like dtd:/W3C/DTD XHTML 1.0 Strict/EN instead of http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd.
Oh well.
Oh well.
It came to pass that the FirstPerson group needed to put together a 'spec' and have it put into some form that wouldn't evolve quite so rapidly as it was impossible for partners (and even some engineers) to keep up. One of the components of that spec was creating a globally unique name space for classes if they were to exist in a global namespace. The 'natural' choice was to use DNS names, DNS was easy, it already existed, and as Bill Joy pointed out "If sun.com doesn't exist we've got bigger problems than where to find our class instances." The counter argument that 'protocols live forever' and another that we should not tie the core of the language to the corporate entity that birthed it, were not compelling. The tertiary argument that as name spaces went a 'layered system', one where a level of abstraction was added to allow for changing the underlying space, would be better than tying it to DNS names, was also unsuccessful. The choice stood.
Its always interesting to 'win' an argument over 15 years later. Doesn't change anything of course, one can either take pleasure in knowing they were right when others were wrong, or feel guilt at not having been more eloquent or convincing in their argument. Of course neither really does any good.
But if you are out there and you are thinking to 'copy' the Java scheme of naming things based on DNS names. Please reconsider, nothing is forever unless you can control all the moving parts.