The reason is fun, and no justification is needed. Maybe you've spent too long looking at the world in a purely progress-driven way. EDIT: I've been there before, but imo the point of progress is to have fun in the end anyway
No, I am precisely not looking at the world in a purely progress-driven way. I think many of creators do - they think they bring a piece of progress to the world, where in fact they might bring regress - in this context, a service which is enabling people to sound like someone else, adding up to the pile of confusion and fake content.