More to the point - who cares. Freaking Jurassic world was awful and its one of the top selling movies of all time now. All this proves is that if you take great movies and update them, people will flock to them. To put it another way - Episode 1 is still in the top 10 in unadjusted gross domestically 15 years after its release.
It's really just a matter of popularity, more than quality. A means of keeping score.
It will be interesting where Episode VIII lands, though.
While Ep. I made a ton of money because people flocked to the theaters to see it (hoping for more of what they liked in Eps 4-6)... it was largely disappointing, and there was a steep fall off in interest for Ep. II. The flip side of that is something like Batman Begins, which led to a huge bump in popularity/ticket sales for The Dark Knight.
Will Episode VIII top even Episode VII, given the massive success of the first coupled with widely positive public opinion?