In reply to Petya Raykovska.

Some strings require adding some HTML, many strings are used in sprintf and require understanding of how sprintf works. This is not a very high barrier, but it is most likely a barrier for professional translators.

It is not hard to do a 100% translation, it is somewhat harder to have a good 100% translation.

And then you have the codex and whatever tutorials that are in wordpress.org that are basically in english but are still being pointed to from the translations.

Enter all the "pro" plugins and themes for which you can not host a translation on wordpress.org, and no one can distribute their translation without the risk of violating copyright (imaginary or real risk, not sure myself, but for sure there is no incentive for that) and you get a UX which is partially localized and partially not.

In a way for the user it might be better to have a full english admin because at least he will be able to google for an error in english, instead of hoping that his translation was good enough for google to do the translation for him.

And all what I said, is that the overall approach to translations needs to be re-thought, not that the translation focused day is pointless.....