We actually keep pretty close to that, but have two implementational differences: 1. Namespaces are linked to a specific directory instead of just translated to a path 2. Our paths are fully lowercase

And I stand by those. The first allows for more flexibility when it comes to code organization and the second makes mistakes in classloading a lot less common. You can disagree with these but we have documented them clearly. Also it's quite easy to add another autoloader, ours won't even do a filesystem check when trying to load from an unknown namespace so it should add hardly any overhead to attach a Zend (or anything) compatible loader.