Well, maybe until Dum-Dum.
I don't deny that my own position is pretty strict. Even with non-ERB heroes. I read a Jame Bond book a few years ago, and it wasn't very good. Still, it had my James Bond in it.
I am so attuned to the ape-man myself that I think I could write a good Tarzan story. I noticed when I first re-subsribed, and copied the prose about how Tarzan never kills for pleasure from "Return", that it sounded amazingly like my own writing. Until the end of the passage, it could in fact have been a post of mine. It even had the words "in fact".
What with "quick is numa", and my own savage nature, I know I could write about Tarzan, or as well as anyone could other than ERB.
That's still not as well as ERB though, and quite apart from quality, it just wouldn't be the same.
I created Tawny in the image of Tarzan and Conan; and although he has characteristics of both, I don't borrow language from ERB, such as "quick is...", and if I borrow language from Conan, I don't realize it. I prefer my character to live according to my own prose.
I prefer to see new creations other than those I have deified in my own mind. Writers who create their own version of Tarzan, or Conan, or Tarl Cabot, with their own unique prose, characteristics, worlds, creatures. It gives the writer much more freedom to express himself or herself, and perhaps to create a character, as did ERB, which is better than those existing (excepting Tarzan and Conan).
To me, as has been posted by Huck and perhaps others, how much more can Tarzan do? That's one problem I have with the Dark Horse comics. They have sci-fi in there, and so on. I'm sure ERB could have come up with a few more lost valleys, and written more GOOD Tarzan books, but not many more.
As has also been very eloquently posted, Conan was a complete saga with REH. Although I didn't mind some of the help DeCamp gave in a few stories to finish them, you could tell when he gave too much.
With a new character, and particularly a new world, endless possibilities exist. Tarak's world is yet to be created, for the most part, and in one book and story I've come up with some interesting stuff which just couldn't exist in a story here on Earth. I just talk about it a bit excessively, as I do in posts.
I admit that these types of stories are not presently likely to make money. If they could, I would do nothing except write about Tarak and party all over the world.
Nevertheless, it seems to me that although ERBs worlds give everyone a framework with which to work, in that several listers can write stories which occur in the same place, with the same kind of creatures, and perhaps even overlap and/or interact, I don't see the same concept with Tarzan.
Irrespective of his image in my own mind, and quite apart from the pretty clear fact that nobody can capture the essence of the ape-man as did ERB, it seems to me that a work about another character, however he gained his abilities, and whatever they are, would be much more pleasurable to read about than an attempt to write about Tarzan doing something else, when even ERB had exhausted much of his potential.
I preferred to do homage by creating a Tarzan-type hero, but with his own unique maturation and personality. He does not compare to Tarzan, or to Conan,, since I don't have their unique talents, but he is not a copycat of either, and his potential adventures and companions are virtually endless. If the goal is to entertain; rather than to make a profit, it seems to me that much more entertaining and original stories can be written about original characters, and sometimes original worlds.
The exercise of imagination, as is the case with all exercise, is best done when a complete extension is achieved, whether muscle or brain.
Although I have less problem with the non-Tarzan stories, and would agree that Barsoom and Amtor provide a very usable vehicle, I would personally prefer to see an entire new world, created by ERBlist writers, trying for once to come to a concensus about certain facts about the world, so as not to conflict; then to have individual writers create their own characters, and creatures, for the world, and stories which feature them. And plenty of princesses. Perhaps because of my own reluctance to tamper with ERBs' worlds, I would be much more inclined to write stories set in such an ERBListWorld, than I would about Barsoom.
Of course, I like writing about Tawny, too, if only for my own enjoyment, and to keep part of myself young, savage, and barbaric.
In any event, in my view a writer can probably write better if (s)he is unfettered by boundaries, and isn't measured against standards which simply cannot be met.
Tarak