Making the script aware of namespace names would be quite easy.
Yes it is more a matter of priority than feasibility.
I already use localized namespace names in wikistats, obviously. Without those the dumps can't be interpreted. Each xml (full) archive dump starts with list of localized namespace names.
I also parse php files for localization of reserved words like #REDIRECT And parse other php files for language names translations And extract many more language name translations from wp:en interwiki links via api.
But every such action takes time, needs safeguards (files can be moved, can be temporary inaccessible, formats change, maybe not in xml, but in php for sure) and requires occasional attention for maintenance.
So for a housekeeping job where really almost no-one seemed to care about at the time, I just chose to keep it simple (this particular optimization can always be retrofitted).
If we find a better place to store them than on the wikistats server we might be able to store them unfiltered, but still condensed as one daily file, as this speeds up processing greatly, or maybe repackaged into a monthly file per wiki.
Erik Zachte