I don't think I've ever heard anyone else make that point, and I haven't paid close enough attention to the dialog to realize it either, so, wow, that really makes a difference. Especially since, at least in English, "ends of the Earth" can also mean metaphorical extent, as in "I'll find that answer even if I have to go to the ends of the Earth". If it acts as a metaphor similarly in Japanese, then it could be referencing something like Utena's willingness to protect Anthy going to such an extent.