That said, I'm going to take all of your criticism with a grain of salt, as I detect some bias. I'm familiar with your work on the Dark Sun knockoff "Dead Worlds" that is altered just enough to get around the copyright restrictions so that you can sell it. If I wanted to follow your advice, I'd do the same and bastardize the setting beyond recognition for personal gain. Instead, I'm going to keep down my current path because I want to play Dark Sun, and not something else.
I can speak to these points.
When I first posted Deadworlds, I didn't want to ride on the tails of Dark Sun setting. I didn't mention Dark Sun anywhere in the first release, because, well, I wanted my work - the mechanics, the art, and the writing - to stand on its own legs and be judged on its own merits. If people wanted to use it for Dark Sun, that was fine - after all, I first started it as my own personal Dark Sun conversion - but there was some cool stuff in there that didn't fit the setting, and I included anyway, partially to differentiate my work and partially because hey, Dark Sun is a post-apocaylptic setting, and things like the "Doof Warrior Bard" fit that kind of setting! :)
The reason I went on to sell it is because I'd spent a year working and iterating on it to the point where I was confident that the mechanics and systems I had created were, in fact, worth people's money. I've got a personal rule that if I make good, solid work, I don't release it for free unless it's for a larger cause. That's just a basic part of me valuing my own time, energy, and end result. When I decided that I was going to sell it instead of releasing it for free, I went back and removed all the references to Dark Sun because of that.
The additional material and lore I added as a part of Deadworlds - the zarraak, firearms, the intro on "how to use this material", etc - actually came about in the form of later updates, to help separate it further. These came in response to critiques that it was too similar to Dark Sun, and I honestly felt they were right.
Overall, I think you got the wrong impression about Deadworlds, and I take the blame for that. It's not intended as a pure Dark Sun conversion, but as a collection of post-apocalyptic fantasy material that includes stuff for running Dark Sun. I made the decision to shift the focus in that direction as soon as I decided to make the personal material I had into something good enough to charge for. Again, this misconception has been been my fault since the beginning - it was the first big release I'd made for the DM's Guild (though now it's on DriveThruRPG - OneBookShelf and I had a talk, and they felt it went too far towards making a specific setting, which I can understand), and I made a lot of mistakes in how I presented it to other people. But it was never my intent to make a profit off the work of others. I only ever intended to present material that I felt was at a high-enough quality and that I had put enough effort into that I shouldn't release it for free.