I agree with the article, but if we say that Cambell is unethical then where do we draw the line in general? Eg. Is Kaggle unethical and exploitation as well ?

I agree with the article, but if we say that Cambell is unethical then where do we draw the line in general? Eg. Is Kaggle unethical and exploitation as well ? Like the Cambell hackathon, in Kaggle competitions you work for free and only a limited number of people actually get paid for their work. Even if Kaggle promotes that everyone's work actually helps (indirectly) to pin down a good solution, not everyone is getting paid.