Years ago when I was working the day shift at the stage door at a local theater while I was in grad school, the mailman came in and noticed that I had a whole pile of graphic novels in front of me to help me pass the time. He excitedly told me about how much he liked Miles Morales and how happy his kid was that Spider-Man was also another nice black kid. While I don't know much about Miles outside of the last Spider-Man cartoon (which, again, I found surprisingly enjoyable despite my initial misgivings), that alone is worth the character's existence.
And I'm willing to bet they're not the only two African Americans comic book readers/cartoon watchers who are grateful and enjoy the character immensely.