That's how you effect REAL lasting change. That's how you create a
new universe. That's how you really pay tribute to Kirby, Ditko, Lee,
Robinson, Kane, Fox, Siegel, Shuster, and all the other pioneers who
actually INVENTED something, and didn't just take what someone
already did and change it.
________________________

You mean like Blue Marvel? In the last 30 years, how many new
characters have been created? How many have reached major
popularity in comics? Outside of comics? And I am not even talking
about minority heroes, I mean any truly unique heroes that are
created, they aren't lasting. A character has a better chance of
succeeding if there is existing familiarity. I don't think the new Blue
Beetle would be doing so well if he was the Scarlet Scarab. Marvel
has created several new characters for their Initative/Avengers
Academy title and there is no buzz about any of them. Periodically we
meet new X-men or new Avengers and when the next writer shows
up, the new guy is gone.

(Seems like Rob Lefeld has created the only one or two characters are
both unique and making it really big at Marvel--Deadpool and Cable.)

There is only so much room at the top for truly popular characters.
Until Spider-man, Batman, and other top players leave, there is no
room for too many more new big names.

Also when Kirby, Lee, Ditko, and even the DC crew in the silver age
created these heroes, they weren't competing against their own
companies' material. Daredevil, Spiderman and so on, where born in
an empty universe. They didn't compete against an Marvel's existing
Superhero universe. Modern day characters are competing not only
against the other companies' characters, but against their own
companies' long term sucesses. It isn't a fair comparison.

I've read that Miles Morales is supposed to be aged only 13. If that's right, it's far more of a barrier to the character catching on as a series lead than his ethnicity.

***

Why would being 13 be a barrier to the character catching on?  What fan is already on-board with this change, but suddenly willing to draw the line at age 13?  DC's Damian enjoys a great following and I think he is even younger.  A 13 year old hero might actually appeal to my 13 year old child (whose interest in comics is waning as it is).  Just, you know, hopefully not this particular 13 year old hero....

And this is part of the problem; in Marvel Thor and Hulk and the top
muscle guys. It is hard for another strong man to find a place with
equal name recognition.

••

Depends on how you define "often". Kid partners have played an important part in superhero comics since very close to the beginning. Jules Feiffer, in "The Great Comic Book Heroes" history of the business pointed out that this was largely due to a complete misreading of the audience by the creators of the books -- kids didn't identify with Robin, they identified with Batman! -- but the kids have long been there.

Marvel took this to a new level, of course. Stan and his collaborators wisely made many of their characters only slightly older than the readers -- the Human Torch, Spider-Man, the X-Men, the Wasp -- while casting adults as villains. And none of their super-powered young folk were sidekicks in a traditional sense. The Wasp came the closest, but she was also a romantic interest, which altered the mix.