Subtext is another thing that sounds boring because it reminds us of high school English class, but it can be a pretty useful tool in writing. It can help guide you when you have writer’s block and it just adds another nice layer of structure to the architecture of your story; another part of the story that isn’t always obvious, but can definitely make it more enjoyable. Subtext is basically all the crap that’s in a story but not explicitly written. This stuff’s juicy for all sorts of reason. It makes the audience think about your story, which makes them more invested in it, and gives people something to discuss about your story other than just if they liked it or didn’t, which also invests them in it. It can also be your very own mind-control device! Okay, I’m exaggerating, but it IS a vector for any opinions you may want to express to your audience and you can bundle it in such a way that it doesn’t seem pushy or arrogant (unlike, say, voicing it). At the very least, or perhaps the very most, subtext is a way of expressing yourself, your beliefs and feelings, through your work.
And the neat thing is that subtext doesn’t have to be intentional at all. Parts of yourself will inevitably seep into your work whether you like it or not. And people will interpret your work the way they want to, even if you tried your very best not to put anything in there that could be read into. Art is all about expression and interpretation and people are going to interpret your story in subtextual ways anyway, so you might as well try to guide that interpretation to where YOU want it.
Subtext is also a way to set up people’s expectations and then do things differently. You want your story to be original and not predictable, right?