I don't understand the felt need to do things like this. If there is perception that a specific race is underrepresented in the superhero area then create new ones that do represent them.
Why change existing ones. It is just not necessary and comes across as quite childish.
Peter Parker was killed off in the series. Miles Morales is simply donning the costume and continuing the services that Parker did when he portrayed Spiderman. Unless you are somehow saying that his successor has to be a white guy maybe? Peter Parker was not replaced as a character, this is a totally new character with his own history and stories to tell. It's a blank canvass and a passing of the torch so to speak. Kind of like the Batman comics when Jean-Paul wore the batsuit.
Peter Parker will be in the upcoming Spiderman movie anyways so unless you are a die hard comic reader (i'm not) then you aren't going to notice the difference.
The character has also been pretty popular so I'm not sure what all the outcry is all about. Calling it childish is kind of a strange reaction.
The same goes for the others in the article.