Um, it's like 11 days into the release. Could you define or describe what a movie that has made a "cultural impact" would look like this early into its release and indicate how TFA fails to meet such standards?
I think it would be hard to imagine a film that has entered public consciousness so readily and so diffusely as The Force Awakens has. The movie has its flaws but it's certainly taking up a huge part of the entertainment/pop culture news right now.
You would have to ask the poster who brought up the term "Cultural Phenomenon" as a way to disparage Avatar.