Basic internationalization still shows the basic language as an option

Question

There's something that I still can’t understand about localization on iOS.

I have this situation, with the internationalization base, and I added the Italian language:

So, Xcode clearly sees that the development language is English. So why, if I localize a file, do I see English as an option?

I mean, if Xcode knows that the base localization is English, why can I still choose English?