I can also give a summary of why the wrappers don’t support namespaces yet.
When the wrapper front end parses the C++ declarations and builds the tree, the tree is complete, and includes all embedded namespaces and classes. So far so good. But the back end only generates Python wrapper code one level deep. Why is this? The reason is that the rules for identifier lookups in C++ are quite intricate. Wrapping a class requires identifying all the types, constants, etc. that its API uses. Given embedded namespaces, superclasses, and scope operators, this is very difficult to implement. I worked on it for a while back in 2012 or so, but stopped when it became clear that time could be better spent on other wrapper features (e.g. support for templated classes).