You say "most of this music does not last" but you're referring to music that was only produced a handful of years ago. It's too early to tell if it will or won't in a historical sense. In the minds of a lot of people below the age of 25, that music left an indelible mark, and very much will last. I'm not sure you've given Katy Perry much scrutiny if she reminds you of walking into a "nice, clean, new McDonald's." Perry's performance is sexually liberated and, if occasionally somewhat tone-deaf (e.g. Ur So Gay) comparatively transgressive. Further, although US literacy could be higher, most people are far from "borderline illiterate." But if you take exception with people not reading more broadly/deeply, consider reading some of the past 10 years of pop cultural criticism where the paradigm has shifted towards applying intellectual rigor to mass culture. You might learn something interesting.