Here's the reasoning... I could subclass translate and write out any calls to ::translate to capture the most common mappings as I "exercise" the app. Sure, I can harvest all the TRANS( macros in my source code, but this is a daunting amount for someone to translate, if they just want to do the most common ones.
It'd also allow me to swap out the implementation if I wanted to(sqlite database with all the converted strings? Google Translate lookups[although I think the API is private now)