No it's not, this is just the Register being the Register. Britain would have worked just fine.
It's similar to how "Yookay" is now a word that has certain overtones that aren't conveyed by writing "UK" which is fewer letters.
Britain is ambiguous. Great Britain is geographically specific. Britland is shorter.
What do you mean it's not. What else would you categorize it as?
It's similar to how "Yookay" is now a word that has certain overtones that aren't conveyed by writing "UK" which is fewer letters.