You know the biggest problem with symbolism? Nobody's going to get it. Or, it'll be so blatant that it inspires the rolling of eyes.
Don't get me wrong. I in fact like symbolism a great deal. Subtle symbolism, not "hammer you in the face" symbolism. I haven't reread The Great Gatsby in a few years, but I've had enough people complain to me about their English teachers and that green light that I'd have to hazard a guess it was a bit too blatant.
I can understand. You want to strike the balance of something understandable and oblique. You want discussion to be made, but an answer to be indicated. Probably.
I've used symbolism on occasion. I use literary references far more often, and I can tell you, nobody gets those. Here I am, giggling a bit that I've referenced Crime and Punishment in my scifi novella (which will have to be edited again. It's be nice if I could strike the balance there, and either trim it into a short story or flesh it out into a full novel. But it just seemed so perfect where it was, at its 19,000 or so words).
I've been doing this "I'm a serious writer" thing off and on for more than ten years now. I'm not counting high school, though I did in fact write nearly every day in high school, with dedication noted by my peers. It's a shame that novel had to be such total crap. In that time, I've had a variety of readers, and an important thing for a snarky smartypants like me to remember is everybody hasn't read the same books. It's not like the good ol' days waiting for the latest Dickens serial to come off the boat from England, where everybody's shared the same handful of novels, gone through The Pilgrim's Progress ad nauseum, etc. etc. There are so many books, and we're all readying different ones. I'm not sure how many of my acquaintances have read Crime and Punishment at all, much less once recreationally and once for a college class.
But symbolism. The thing that inspired this post was my recent reading of George R. R. Martins A Dance With Dragons. It took me a long time to start the book (it was published years ago) and it took me a long time to finish it once I started. But there were two chapters which were clearly meant to relate to one another, wherein two characters both took...let's call them Significant Walks. I don't know if editing and timeline constraints made these chapters happen too close together (like, was one supposed to be in A Feast for Crows? Was the other supposed to be later, in The Winds of Winter?), but the fact they were meant to be Symbolism™ really struck me.