The KDE translation system needs such in-source translations to be added to the translation database directly. This is a work done by the translator teams, but who first need to see the original string.
The daily-run translation updating script (called scripty) will extract any strings to translate and update with strings from the translation database, but also remove any translations from the sources which are not in the database.
So adding translations here directly will result in scripty removing them simply on next run. Thus no use to add them -> remove all here :)