Why the compiler dosen't enforce correct module declarations?

[Ary Manzana]

Manfred Nowak escribió:
> Ary Manzana wrote
> 
>> In 
>> http://www.digitalmars.com/d/module.html it states:
> 
> | The ModuleDeclaration sets the name of the module and what package
> | it belongs to. If absent, the module name is taken to be the same
> | name (stripped of path and extension) of the source file name.
> 
> Please read carefully.

So what's the point of settings a package and module name different than 
what's in the filesystem?