Thanks to GCI feedback, I just discovered in order to add languages, bio, location and all the other useful info on the editor page, you have to go to Edit Profile after creating the account - something that's not hinted or indicated anywhere as far as I can see. That's probably the reason so few new users seem to have any of this information!

We really should allow entering this during the account creation process - either by adding (optional) fields to the account creation form, or by sending the new user to account/edit, rather than the main page, after account creation. If we do the latter, we should probably hide the email field when coming from account creation, since it'll confusingly (for the user) show as empty until they verify even though they just entered their email.