Regarding the parsing of URLs, this is a common, but mostly counterintuitive argument: Take for example names in most western countries, addresses (street-zip-city-country), etc. Most of our most important identifiers work this way.

Regarding lacking binding of identity: On the other hand, this has been one of the most important features of the web, from the very beginning. Also, there is no way to setup a system, which will attribute to a single person in a readable and intuitive way. (E.g., names fail to do so.) Arguably, this should be left to (optional) extensions.

I'd argue, the knowledge required to parse a URI safely may be conveyed in couple of minutes. Why not enforce this knowledge? Why not have a URL-parsing note on the start screen of any browser? Why dumb down the system and introduce ambiguity – and by this even more insecurity – instead of educating users? URL-parsing is a vital skill, which can be acquired in less time than memorizing a basic table of partial addition results. Why do we still try to teach addition, if we can't teach URLs?