According to a source who spoke with Yahoo Sports, Nike began a movement to pull the shoe from stores nearly two weeks ago after Kaepernick and others raised concern that the “Betsy Ross Flag” printed on the heel of the company’s 4th of July-themed Air Max 1 was not only racially insensitive, but had also been adopted by some groups such as the Patriot Movement and Identity Evropa (pronounced “Europa”) allegedly as a symbol of white nationalism.
So nike had it brought to their attention that the flag given the time period is racially insensitive because... (let's celebrate the 1700s... when... hmm right that wasn't a great time maybe let's not) and then its use as of late is with white nationalist. Why would any company want to use that?