Even though I didn't like the film, you're missing the point.
The beauty of fiction is that ideas that cannot be explained/rationalized can be explored.
Things like "the flux capacitor" are not absolutely central to the story. But how would you like to watch the movie if characters were time traveling in the Delorean like it's no big thing without the Delorean ever being explained? Even if one character at one point in the movie says, "This thing allows time travel!" Would that really be enough? Wouldn't you need just a little more than that? We may not know how it works or how "the flux capacitor" works, but we do know that the Delorean is something that allows time travel and something that the characters have created. In fact, we even
see the characters working on it. They give us enough information for us to say, "OK, I get it... let's move on..." It could be my OCD, but I would
hate to watch a film all about the zany time-traveling adventures the characters get into without a
good enough understanding of what's going on, that bit of back-story.
Inception, in my opinion, lacks that back-story. It's not a scientific explanation by any stretch of the imagination. In fact, "explanation" may be the wrong word. In fiction writing, we like to say, "show and don't tell." Well, Inception, in my opinion, does neither one, and that's really discouraging. It drops you into the middle of the action and sort of leaves the audience to make heads or tails from it...
EDIT: And please just take my word for it that "the beauty of fiction" is
not something I need explained to me.