The difference to me is that, in Trek, Roddenberry had a very specific vision he was trying to communicate. Starfleet had an ethical code, Earth had become a post-scarcity society, and while everyone knows it certainly wasn’t the best science fiction out there, Gene and the people who worked with him and inherited his vision mostly agreed and just got it. I think a large part of the fandom does, too - at least, those who go out of their way to wear merch to some everyday thing. I’d trust the morals of someone in a Starfleet shirt faster than I’d trust those of someone wearing a cross around their neck.

Star Wars on the other hand was just a fun movie. There’s some Jedi stuff that the writers were never super clear on, but that approximated Lucas’ idea about samurai who were space zen.