Like and Leia also act like they know everything they care to know about Snoke.

And my point is that for decades A New Hope was treated like a sequel to unseen events, and it wasn’t confusing. When the explanation came of how the Empire rose, most fans rejected it. Also, again, the difference is that the characters we know and interacted with were directly impacted by the events of the prequels. There’s no shared history with Snoke, so it doesn’t matter.

Take a Legends/EU example: the Yuuzhan Vong aren’t really explained. They just come from far away. Over the course of those stories they kinda delve into pertinent details, but they’re not giving all of this unnecessary information just to fill out more pages on Wookieepedia.

If that backstory reveal doesn’t affect what’s happening in the current story: it doesn’t matter. Snoke’s backstory never impacted the current stories being told. Pre-TROS continuity had him as an ancient dark force calling out to Palpatine from the Unknown Regions in novels and games. But what would such a reveal in the film matter when talking to characters that were born after Palpatine’s death? What would it matter to Luke and Leia who were concerned with toppling the Empire and restoring democracy to the Galaxy in the OT and have to help or not help do that again? When did they state that they’d defeated the Dark Side of the Force? Where does this plot point come up that you’re so attached to?

Again, it’s just for fans who want to fill out Wookieepedia pages. It did not serve the actual story being told. If you’re mad that we got the stories we got, a lot of people are mad at JJ Abrams for his decisions to do an off-brand A New Hope story and reset that status quo. The problem isn’t Snoke and the First Order, the problem is hiring a man who can’t write to be co-writer and director.