What would the argument be that some workers in the economy but not these people specifically deserve a minimum wage? I get that they are designated contractors

What would the argument be that some workers in the economy but not these people specifically deserve a minimum wage? I get that they are designated contractors but it seems pretty arbitrary. People would lose their minds if they found out Amazon was paying warehouse workers $2.50 an hour but couldn't they just arbitrarily assign prices per package and call them contractors as well?