Oracle is a Corporation. As a corporation, it creates or buys some frameworks or languages in order to maintain its product, or simply to profit. Some of the languages presented by Oracle Corporation are "PL/SQL" , "Java" to name a few. If you develop something over Java language, you are a Java Developer, not Oracle Developer. Likewise if you develop something for your PC that have Windows operating system, you will be C Sharp developer (name of language) or WPF developer, (name of framework) not a Microsoft Developer."software developer on Oracle stack" would be a proper definiton. It would be a technical issue, so it could be a bit confusing.
Today humankind uses many computing products that make sense our life, decipher enemy text, or explore Mars. We owe this outstanding tool to distinguished scientists such as John von Neumann, Alan Turing, not to corporations.