This is an interesting topic for me, because I'm not North American. So, for me, straight white guys are just as interesting as any other ethnic or cultural group. That said, there's an awful lot of them out there...
I think diversity is not so much about the individual characters, but more about the world the characters inhabit. That's what makes Kamala Khan interesting - she's not just one "non-standard" character in a standard white comic, she brings her world with her.