I'm writing a Gatsby argumentative essay from the opposite side
Is this for an English class? What do you mean?
I write the essay as if it were written by a person who hates Gatsby
It is good to write creatively from a different perspective. You should be open to criticism to help edit your story.
Just because you can't think of anything negative about it doesn't mean it's not there.
I guess it's extremely creative indeed to try and force an argument out of something. As long as it's done for recreation and academics, I don't see any harm in it. Hope you can create some cool writings with this.