I think the thing that it really all comes down to for me is that GE takes itself too seriously. Given the fact that it is located in Disneyland where everything is built to be sort of realistic but caricatures of what they represent like Frontierland being a romanticized representation of the old west and so on. Cars Land does just that, they don't try to say that we are living in the canon timeline of the Cars universe which could lock them into certain decisions. Added on that is like mentioned before they only use Disney Star Wars which has notoriously had poor reception compared to classic Star Wars. Yes everyone can argue they actually liked the sequels and think original Star Wars is boring, but we haven't seen the movies have the cultural impact Star Wars did when it was released and when the rest of the original trilogy movies were released.
The fact that it is in Disneyland is what bothers me the most, because you could make the argument that Pandora also takes itself seriously and is canon in the Avatar timeline but aside from the fact that people didn't care about Avatar story-wise that much, I think the park it is in is what allows it to take itself more seriously. I bring Pandora up in the GE debate a lot but I think it is a valid point, Animal Kingdom does take itself more seriously than castle parks like Disneyland and Magic Kingdom. That's why I think the more serious, "realistic" style of the land works, it meshes with the other areas like Harambe in the park that are also realistic depictions of real world areas (however realistic you want to argue it is, but it's not a polished idealized representation like NOS for example). But because GE is a bleak, war torn, hyper realistic / serious land that is surrounded by so many charming lands that don't take themselves seriously, it seriously sticks out in a bad way. It would be like if Disney had the Fairy Godmother walking around in Fantasyland forever and because she is from Cinderella we can only have the same few Cinderella characters, but we can't even have the main character everyone loves walking around.
I definitely think they have the framework to make the land more enjoyable, even if they removed the canon status and allowed walkaround characters of Darth Vader, Luke, Leia, Han, etc. we would have the same land there. I would love to see more characters and to have things tied to the OT and heck even the prequels, but that wouldn't fix the land. I have loved Cars Land since the first time I visited it, the neon signs at night are so incredibly beautiful and seeing the cars driving around gives the land a very unique aspect to it with fun kinetic motion. I also really enjoy the ride system, I think it's a good mix of darkroom storytelling and thrill. I love the indoor section, they just have fun with the ride. It isn't realistic you drive into the cave and then end up back on the main road in Radiator Springs, but I just think seeing the area at night with all the cars around is super cool.
