Who exactly decided that reposting others' content, with citation, is unethical? The people getting credits are getting an opportunity to grow their follower co

Who exactly decided that reposting others' content, with citation, is unethical? The people getting credits are getting an opportunity to grow their follower count and to gain more exposure as well. If they aren't happy with what he's doing, they can certainly flag his account, and Instagram will eventually ban him if he gets flagged too many times. A lot of the responses here are dripping with envy and sour grapes.