Thanks!
I think the difficulty comes in identifying what that "core spirit" of Star Wars is. To me, it's something beyond just the structural elements of, say, a plucky underdog military against a vast oppressive regime. Likewise, it's more than just "Jedi vs. Sith" and such. Most of that is window dressing for deeper stuff.
I think the struggle to define this is what lies at the heart of the current tensions within the fandom. For some, TLJ deviates too much from the core spirit of Star Wars. I don't see it that way, although I do see it as a deviation from the core. It doesn't go
too far for me, but it does deviate.
I think what illustrates the core spirit of Star Wars is a few things.
First, it has to have some kind of spirit of adventure to it. Star Wars isn't "My Dinner with Andre." It's not a courtroom drama. I mean, you could have a courtroom drama set in the Star Wars universe, but unless it was part of a larger story, that alone wouldn't really be a Star Wars story as much as it is a story with "Star Wars" slapped on it. The nature of the adventure doesn't always need to be identical, though. It could be a commando raid, a heist, a "space western" that takes place on the frontiers, but there's gotta be some sense of excitement to the story and some sense of journey involved.
Second, it should address certain themes of good vs. evil and the choices we make in navigating that duality. It's worth noting that the duality doesn't necessarily mean polarity. You can have stuff that's morally grey. Likewise, with the Force, while there can certainly be a Light Side and Dark Side, I don't see the necessity of erecting some kind of wall between the two where you have to always be on one side or the other of that divide, or forever give yourself over to evil. But at the core, there ought to be moral decisions that characters have to make about whether to do something for the right reasons or for the wrong reasons, and exploring the consequences of those choices as they play out within the context of the larger adventure.
Third, you probably want to involve some kind of mysticism. I don't think this is necessarily an absolute requirement, but it definitely helps with the overall feel of "Yeah, this is a Star Wars movie." The problem with midichlorians was less that it was a retcon, and more that it was something that seemed to strip away the mysticism of the Force and turn it into a matter of biology. You can find ways to kind of limbo or tapdance around that problem (or just say "Yeah, turns out the Jedi were wrong and were mistaking correlation for causation"), but at the end of the day, the Force isn't science -- it's space magic/mysticism. HOWEVER, mysticism can be introduced in other ways, and we've seen some of that in Rogue One (with Chirrut Imwe's mystical abilities) as well as in some external canon stuff like how the Nightsisters of Dathomir relate to the Force and such. Basically, you don't have to be a Jedi or a Sith to use the Force, and you don't have to necessarily use the Force to do mystical stuff (or at least you don't necessarily need to believe you're using "the Force" and may call it something else). Concepts of the Force can be expanded beyond simply what Yoda and Obi-Wan described, too. Personally, I like the distinction between the Cosmic Force and the Living Force, but I think you can play around with the concept of the Force and ultimately determine that it's bigger and perhaps more unknowable than has been portrayed. That need not invalidate what other characters have said, but rather it can suggest that their description is right insofar as it goes, and there may be more beyond what they described or their description may be accurate but incomplete.
Finally, I think the core of Star Wars has to involve the "good guys" being friends or at least having some sense of cameraderie. The characters have to actually seem to care about each other, even if that sense of caring develops over the course of a film. So, sure, do your Star Wars rendition of "Pale Rider," but recognize that your Eastwood stand-in has to convey that he ultimately cares about and will protect the people of the village or whatever. Do your Boba Fett film, but recognize that he has to work with a crew of likeable characters that we get a sense he cares about on some level, even if he remains an amoral mercenary.
You can probably stray from some of these elements, but you definitely cannot ditch them all completely, and the farther away from them you move, the less your film is a Star Wars film, and the more your film is a film with Star Wars decor.
--edit--
Something else that occurs to me is that the film should probably have a spirit of optimism on some level. Even if it ends with tragedy, it should do so with a sense of hope for the future, that this isn't the end, and that things will turn out right in the long run. I think this is one of the areas that TLJ deviates the most from this core. That's not to say that it's hopeless at the end, but rather that you get the sense at the end of "Oh man...they've got a LONG way to go if they're gonna actually win this thing..."
