I don't disagree with much of what you are saying, from the point of view of many people, and in fact, in a society in which money rules pretty much everything, I would expect ERB Inc. to take whatever position will bring in the most bucks.
Never for me, however. I freely admit that I am a purist when it comes down to my favorite creations. It doesn't matter to me that a good writer could write a good Tarzan story. I think I could write a good Tarzan story myself. It would be different from ERB, however minutely. No matter how many "quick is Numa..." sayings, and grim half-smiles and so on I could lift as examples of ERB's Tarzan, and put in the story; it would be different, and someone like Usha or myself would immediately recognize it as different, even if we didn't know it already. My Tarzan is 100% ERB's creation; My Conan 100% REH; My Bond 100% Fleming; My Gus McRae 100% McMurtry. Any additional sentence, or page, or chapter, not written by the creator of these characters simply dilutes the character in my own memory, and I won't have these favorites of mine diluted at all. Not for me.
My memories of Tarzan of the Apes will always remain within 24 books; although I have fond memories of a different Tarzan, and one I could also accept, as a comic book/strip character. This literary form is an acceptible pastiche for me, and keeps the character alive without diminishing the real Tarzan of the Apes, which can exist only in the books of Edgar Rice Burroughs.
I was so startled by ERB's Tarzan when I first read what he was actually like that I will never forget it. One of my favorite all-time comic characters suddenly became almost god-like to a teenager. Many of the "faults" which Tangor describes are precisely the unique aspects of the ape-man which drew me to him so strongly. The savagery; the sheer arrogance; the absolute indomitability; the fierce individuality; the primal sense of justice. ERB captured these concepts in prose which forever made Tarzan my all-time favorite fictional creation. Obviously I feel this way, from the way I post.
I don't want to read about these characteristics, these descriptions; nor any actions taken by the ape-man; or thoughts, which were not put there by ERB. I don't like it with Conan, and I stick with the original Conan books for him, as I do with Tarzan.
I don't disparage others for enjoying them; nor that they would lobby and/or create an atmosphere in which pastiches will be written, whether good or bad, for the masses. I don't control the world, and people should (and do) do what they perceive is in their own best interests. All authors die, and lose the right to say what they think ought to happen to their creations.
For me, however, as for books; there is only ERB's Tarzan. I have no interest in any other, nor do I think does Usha.
Tarak