Officially Unofficial

A question--now, correct me if I'm wrong, here--but isn't the author the only one qualified to write a sequel to his own book?

You've seen them, right? Those books that are the "official sequels" to classics, but are written a hundred years later by a completely different author?
How can a complete stranger write a book with the same voice and vision of someone they've never met? Even if they did know them, they can never write just like them. And even if they tried, that too would be an atrocity.

Take "Peter Pan in Scarlet", the official sequel to J. M. Barrie's beloved tale. I could understand if it was the great-great-grandchild of Mr. Barrie who wrote it.
But no.
The person who wrote it was not even related to any events of the author's life. The copyright for Peter Pan was given to the Great Ormond Street Hospital. And they just chose a random author to do an "official sequel."

It's not just that, but when these official sequels add new characters...Well, that just chaps my hide.
In "Return to the Hundred Acre Wood", the author decided that A. A. Milne had failed to add enough female characters. And so they introduced Winnie the Otter.
And even then, the artist attempted to copy Ernest Shepard's illustration style.
Copy, copy, copy...Can't they come up with something original?

Or even the official sequel to "A Little Princess", called "Wishing for Tomorrow".
Now that is what I call an unnesecary sequel. What more is there to tell?

Now don't get me wrong, not every book based on other stories are atrocious.
I mean, look at the Robin Hood and King Arthur legends. Books are churned out almost yearly that are retellings of the famous tales.
Because there never was any set author for the legends, it seems appropriate that other authors will have their versions and visions.

But to me, trying to emulate a writer is just wrong.
Really wrong.