Pop culture is culture. It IS literature. Every book you ever read for English class, every play and poem and short story, it once was new, and fresh, and contemporary.
Shakespeare was like the Whedon of his time (or the Kripke, or the Rowling, or the Moffat,…
Let’s be honest: a lot of Shakespeare was the WWE of his time.
It’s not just that pop culture is literature. It’s that literature is and always has been pop culture. Some of the things we’ve canonized and enshrined today was underappreciated at the time and had to be “discovered” by new critics, but most of it, the reason we know about it is that it had widespread appeal in its time, which means you’d better believe someone was turning their noses up at it and calling it the ruination and downfall of the art back in the day.
Shakespeare wrote things that people wanted to see. I’m not saying there was no artistry to it, but he didn’t put all the jokes about genitals in there because he thought it would make it into a textbook.