Hello colleague, in the first order i think this could be emulated by a dictionary mapping the row name to an index into a matrix or DataFrame. Afaics calling this a 'misfeature' comes from trying to make a matrix datatype that has row names by default and many people with numerics/engineering background reserve the name matrix for the simplest possible form: rectangular array with single number entries and integer row and column indexing.
So what you look for: a rectangular collection accessible with both row and column index as names is something new and should have different name. You could browse the dataFrames development and see if there are enough hooks to extend this. Bringing this into julia as package (written in julia) should not be that complicated if defined clearly (but still, someone is needed to implement).