They are purposefully laced with theme and symbolism by the creators.
And at least in Nolan's case, can be quite easily enjoyed without it. I'm going to assume you're just not a writer and you don't know what you're talking about because it's probably the most generous thing I can say about this little outburst of yours.
Symbolism is in the hands of the consumer. It's something they read out of a text. You get all deep and symbolic and you have three options: it works and is recognized, it doesn't work and it's recognized, it doesn't work and it's not recognized at all. One of them makes you look like you're blowing on a broken whistle, one of them makes you look like you're trying to show off, and one of them still makes you look like you're trying to show off but we'll forgive you for it.
That's symbolism. Getting thematic is even more dangerous because the next thing you know you're writing the second half of
The Jungle and it's impossible to take the work seriously anymore because it's being clearly engineered. (For FS2 examples, see the violent reaction one of TopAce's efforts got about this very problem.)
Good fiction is good narrative first, anything else second. Good narrative is not beholden to symbolism or theme or any other literary device. It is based solely on the ability of the writer to present a coherent and engaging story. Nolan is a good storyteller because he knows how to do that. Micheal Bay is not a good storyteller because he's not yet figured out how to be coherent, though on his good days he's engaging until the next screwup.
F. Scott on the other hand is selling a gimmick. It's a good gimmick, quite well done, but it's only a gimmick. Once it fades the core of his work just isn't worth the mentioning, unlike, say, Hemmingway. (Who I hate, but on a philosophical rather than a craftsmanship level; it's not that he writes poorly but what I read out of it in terms of theme is both alien and abhorrent to me.)
