The appropriation argument is somewhat unsound. Creative endeavors, by definition, build on what's come before. This isn't any different between code, creative writing, drawing, painting, photography, fashion design, music, or anything else creative. Creation builds on what came before, that's how it works. No one accuses playwrights of appropriating Shakespeare just because they write a tragic romance set in Europe.
The hyperbolic way you've made whatever arguments you had, though, is actively working against you.