A lot of the examples posted here are derivatives of established characters. How many completely independent non  related,  characters have been created?  Maybe Sentry ?

Not to speak for Icctrombone, but perhaps he's thinking of more directly derivative characters - directly in the way that, say, Supergirl is derived directly from Superman; or, in another way, a new Spiderman or Captain/Ms. Marvel might be a new character in one sense but is directly derived from the established character in another sense.

This would seem to be borne out by his counter-example of a non-derivative character, Sentry: myself, I would have thought that character, in yet another sense, one of the most derivative characters you could name, but obviously that isn't the kind of "derivative" he's talking about.

So putting a fresh coat of paint on something already existing and calling it by a different name makes in not derivative or a copy and certifies it as an original creation?

Kamela Khan is much more different from Carl Danvers and a much more original creation than Batman/Bruce Wayne was from the Shadow/Lamont Cranston, but because he was called Batman not the Shadow and wore different clothes, he is original but because Kamela uses the Ms. Marvel name, she is not?

-M

These days ALL writers and artists are thinking of the long term and profitability of anything they create. Variations of already existing characters is the safest most ingenious way of "creating" anymore. Attach or insert a new name or person into already existing mythos and half the work is done for you. What are many writers doing now in other companies? Creating entirely new worlds focusing upon story and various characters mostly WITHOUT a main Superhero as a selling point. And when a new "hero" is created it is less for the comic book and more about the movie/television potential. How long will Hollywood continue making Superhero movies from already existing characters when they figure out they can still do superhero movies without paying for them?!? That same logic applies to the comic book world since writers and artists figured out: why let a company have control of your idea and profit from it when you can and should be the one doing that?

Publisher's like Marvel and DC are existing off already created characters which they exploit as best they can while hoping to draw new readers and buyers. In the old days, creators could turn to the newspaper syndication for keeping control of their ideas and these days it is self publishing or Image publishing for the most part. The existing publishers who controlled the comic book industry in the olden days would crank out all they could when something caught on and make their cash until that venue faded. Look at the past in how it all went from craze to craze: Pulp heroes, crime stories, horror, mysteries, funny animals, westerns, science fiction, fantasy, back to superheroes and with each craze something "new" would be created. These days, there are no "NEW" crazes anymore, just repetition of the same trends coming and going in momentary sales blasts. 

When the corporations ruled the news stand as a creator you really had no choice but to work for them and give them your creations as you went along. Now the rules have changed with the internet and having cash backers buying into your ideas all before you print anything. Where creators couldn't afford to self publish on their own in the past unless they were a "big name" or had a publishing house to back them now just about anybody with their own idea can get their work out to the public. 

There will always remain some new character coming along from the "big two or three" but more often than not it will be current takes on already existing characters. The company Ditko's and Kirby's who had no choice but to putting most of their ideas into company projects are no longer around when you can move freely from place to place and get your stuff out there in other ways without letting your ideas being owned by anyone other than yourself.