We don’t need to have everything explained by the film. There are other non-film sources with which to draw on for relevant information to people who would care.
Those other sources aren’t canon.
And why do you need an officially-canon explanation? Why are explanations for things subject to the whims of the production studio? Lucas at one point said The Force Unleashed video games were canon. I don’t know if they still are. And recently the powers-that-be said The Clone Wars tv show is canon. But all of the once-EU-now-Legends material is considered worthless for giving in-film events explanation or backstory?
If you so desire explanation for why something works the way it does or why an apparent inconsistency has occurred, why do you only accept the official answer given by the studio in the form of film rather than working it out with other hardcore fans (including book authors) to come to a conclusion that makes sense to you?