WP should provide a database of text strings for themes

I downloaded WP in a foreign language, and everything was perfect until I decided to download a theme. Here I reliased that every single theme hard-codes its own text strings in English. Furthermore, those text strings are almost identical from one theme to another : “Leave a comment”, “Your email:”, “You must be logged-in to leave comments”. This begs the question : How hard can it be to establish a database of those text strings, called for example “WP Standard”. All themes compliant with “WP Standard” would then borrow their text strings exclusively from that database, which would be available in many languages.