Pornography is subjective, but typically the product of Pornography is to entertain on a sexual level before anything else. If a story is "pornographic" in nature then that could cause problems. Just because a story has a lot of sex though, doesn't make it pornographic if there is substance and "story-line" that accepts the sex within it. Throwing it in for the... "smut" factor in my own opinion, not as a moderator... would be bad for the site.
But, if a story is violent, sexually expressive, or anything else, GA has warnings, labels, and rules around those in place that is to protect the minors as well as the adults that just don't want to read them. Members should though, think about their works before posting... and do the right disclaimers, labels, and maturity ratings.
I do write some sex scenes in my stories, but I don't consider myself a writer of erotica, because that's not my purpose...