The point here is that there are more consequences when you're Black in the US. Statistically speaking people of color, and in particular Black Americans, are arrested and convicted of marijuana related crimes at a much higher rate than any other group [1]. That translates into Black Americans being kept out of the newly legal business because of racist policing policies.
[1] https://www.washingtonpost.com/news/wonk/wp/2013/06/04/the-b...