Hi Markus ,
Your are right in assuming that the Language section remains for users who are going to manage the backend languages there.
However, your suggestion to add an explanatory message is very good. We added a task to our backlog (ID 108375) and plan to implement it in some of the coming releases.
Thanks for noticing this omission. 500 points were added to your account as a sign of gratitude.
the Telerik team