@instance method: I think there are cases when you want just a 'humanish' name from the plain string without the need to create an instance of URIish and running through the validation. May be even for an invalid URI, you are interested in a 'humanish' name only and don't care about anything else.

@method's name: what about the path of least resistance? ;-) There are three contexts when you may want a 'humanish' name: git, UNIX and java.io.File/IResource API. -1 for UNIX as it requires some specific 'knowledge' about it, +1 for Git ('humanish' is a domain-specific to Git and should be known for a developer), +1 for java.io.File/IResource API (you are trying to work with the underlying filesystem and should be familiar with domain's specifics).