Made this by slightly changing up some of the ingredients (more veggies, some file powder, all sausage etc) and it was good. Don't know why a "Cajun" cook wouldn't make this....other than it might be "Creole" in nature 'cause of the roux base. There are SO MANY kinds of gumbo with MANY different styles and bases (roux, file, etc) it's really hard to say it "can't be from LA."
I love this recipe. I have used it several times and always enjoy it. I used shrimp instead of sausage and it was delicious.
Don't know where you got this recipe, but it was not in Louisiana. No self-respecting Cajun cook would serve this. NOT GUMBO.