Non-Spanish European powers used the Black Legend to highlight the unspeakable cruelty the Spanish inflicted on Native Americans. Why would they want to do that?

The Black Legend was a historiographical phenomenon that was made with the main goal of discrediting Spain as the leading European power in the 16th century. Non-Spanish European powers took advantage of this and used it to highlight the unspeakable cruelty the Spanish inflicted on Native Americans in order to justify their own attempts to colonize the Americas and portray themselves favorably, and in term taking the publics eye off of themselves.