This idea has already been suggested before in many forms. In the future, please search the forum to see if your idea has already been suggested before you post it. This helps to prevent the forum from becoming cluttered with duplicate threads and allows the developers to more easily see which ideas are the most popular.
Here are the links to the older threads: Pirate Maps
and NPP (Noobs Protection Plan)
Although this second thread is not exactly what you are proposing and is closed and unavailable for comment, I think the reasons stated in that thread against the suggestion are valid reasons against this idea as well. There are quests that would be impossible to complete should we extend the safety zone as you are suggesting.
Feel free to go to the Pirate Map thread and add your thoughts/suggestions.
Have a nice day!