Well, I don't know that it was entirely appropriate for her to make that comment, especially after being asked about her being Green Lantern. If she knew anything about Green Lantern she would know that ANYONE can be Green Lantern (man, woman, alien, owenshooter...). The story for Green Lantern can change, and I would be perfectly fine with a female character portraying Green Lantern.
Switching the story up is nothing new; however, usually when Superman or Spiderman or Batman needed their stories switched up (or down) the character introduced would be their own separate character (Batgirl, Spiderwoman, Supergirl). Lot of times comic book creators will start a new line of "alternate reality" comic books. Of which, usually new artists are christened into the comic artistry business. Many great comic book artists and writers started out doing "alternate reality" comics. The comic book companies use these opportunities to not only discover future talent for their administration, but to delve into new ideas that may or may not be marketable.
Let's take Ultimate Spiderman. Peter Parker is still the original Spiderman, but the creator of Ultimate Spiderman was African American/Puerto Rican descent and is one hell of an artist (although he doesn't draw Ultimate Spiderman, he is the writer). They let him run with his Black/Latino Spiderman to debut his talent in story creation and also Stan Lee thought it was good to show diversity.
Eventually, these individual's that Rodriguez thinks is "stealing" white people's superheroes will come up with their own stories (and probably already have); but it isn't about Latinos or Blacks or Asians or Females stealing White Male Superheroes...it's about Marvel or DC allowing them to go ahead with changing the story.
Take a look at Todd McFarlane...perhaps one of the best Spiderman artists to ever hit the scene back in the '90's. Don't you think he and his schism of artists had their own ideas and stories? However, Marvel didn't allow them to do these things that they wanted to. They had to stick with Spiderman, Hulk, XMen, XForce, etc...
When Todd jumped ship, he started IMAGE Comics and was finally able to express his own, original series (although you can see the Spiderman influence).

When it comes down to it, who really cares what Marvel or DC wants to do with their "white male heterosexual superheroes". It's their superheroes, not yours or mine. We might like them and we might fall into the marketing for them; but we do not own them. And if we don't like it...guess what? We probably aren't going to see their movies or buy their comics no matter how great the writing or art work is.
I am not saying what Rodriguez said was entirely wrong (and she did a good job explaining her stance), but it isn't about minorities stealing white people's superheroes...it's about the comic book industry allowing stories to be changed. They are the ones to blame, not the minorities.