Well, IMO it is possible to judge objective stuff like camera work, the plot, special effects, acting, and a lot of other stuff (most of ehivh have categories at the Oscars), basically the "tools of the trade". There are loads of movies that were not very successful in the theater for a number of reasons but are "good" and other ones that are really bad in many aspects but popular.
And frankly: Star Wars is a phenomenon. It just is. For a lot of reasons. But judging by many criteria the stories are mediocre at best, and have always been. So for example if anyone complains to me about plot holes or lazy writing in the current Star Wars movies I just point them at a few equally bad things in older SW movies that had to be filled with stuff from comics and the universe built around the movies years after that.
In the end I still think that popular and good have to be separate. Just with the added reminder that liking something that isn't good by objective measurements is not wrong. Example: Top Gun is a godawful cheesy movie in many aspects and I still love it. Nothing wrong with that.
Counter example since you mentioned it:
Annie Hall is a brilliant movie, better than Star Wars in almost every regard that you can objectively measure, and it rightfully earned best picture that year.
I still don't care about it.
It is like in the year the first Lord of the Rings movie was released. It was great but IIRC the best picture award went to "A beautiful mind", and rightfully so. Even though as a fantasy fan you just have to shake your head.
