What makes a guilty pleasure? Is it something with poor critical reception? Or just anything you'd be embarrassed about? Why would you be even embarrassed about liking something, anyway?
Everyone has their own guilty pleasures. It could be some movie you can tell is dumb but you enjoy anyway. Or a song that's cheesy and generic but you can't stop listening. You know it's not of "high" quality but you still like it. It could be a reflection of how we let the external world validate ourselves. But in most cases, I think it's our own internal sense of self that makes us self conscious about these things.
You shouldn't enjoy cheesy pop songs because you see yourself as an avid music fan. Or you're an independent film fan who analyses movies intensely, you shouldn't enjoy the obviously shallow action movie. There's an internal conflict between how we view ourselves and the image we'd like to portray. So we keep these likes hidden, only sharing them with a healthy dose of qualifications.
Guilt is apropos.
But why should it matter anyway? Human beings are nothing if nuanced and contradictory. We don't have to make sense. Instead of feeling guilty about what we enjoy maybe we should all embrace it and share it without any explanations. We can enjoy the good and the not so good, and still be whoever we view ourselves as.