Why UE doesn't make use of namespaces?

This docsite states that unreal engine currently is not wrapped into namespace(s), I would just like to know what is the reason behind design of putting all the engine code into global namespace?

Also is it possible that in the future engine code will make use of namespaces? (currently keyword from the link implies that)

Doesn’t prefixing classes with letters look like C style coding?

There’s already modules and dll export / import everywhere. Add to that platform dependent code, no need for more layers ontop of all that.