Why do so many of today's pop hits sound plucked from bygone eras?

Pop culture is inherently "pastiche".

To think of pop culture contextually, it's really only been a phenomenon we've experienced for the past century or so, depending on how you want to define "pop culture", but I'd say the advent of radio and cinema would be a good starting marker.

So, making claims about what pop culture is "supposed to be" are somewhat frivolous since we are still very much in the process of defining that. However, at this specific point in 2015, I would agree that we're falling into "an emptiness in contemporary pop culture" more so than ever before - but that emptiness has always kind of been there.

Take Elvis, for example. The author made repeated examples of Bruno Mars and Pharrell, but in a more abstract sense of the term, Elvis was the king of pastiche, most of his hits either being Blues/R&B/Soul covers or written by someone else. Considering Elvis as one of the first major acts in manifesting the phenomenon of pop culture, it's pretty fair to identify pop culture as an entity which capitalizes on previous work. The Beatles, Michael Jackson, Madonna, Nirvana - the most successful pop acts have followed a formula of commercializing genre tropes.

I understand the author's main point that, in the most current critique of contemporary pop music, the 2010s feel more empty and less innovative as opposed to having a branded identity like the grunge of the early '90s, the (now retro-)futuristic visions of the '80s, et cetera. While the "EDM" movement may refute that, I think the bigger issue is that with today's level of exposure to different cultures, Americans are less "forced" to subscribe to pop culture.

Innovation doesn't happen in pop culture - pop culture just capitalizes on it and brings it exposure. Nirvana were a talented group but hardly the first "grunge" band, and if you've seen Dave Grohl's Sonic Highways, Sub Pop was actually a little surprised that these guys were the group to nationalize the grunge scene, when several other bands under the label were just as qualified. Michael Jackson was obviously talented as well, but a lot of his success can be attributed to Quincy Jones building off Disco's pioneering and nudging it into a "poppier" format.

Maybe we're reaching a point where the general public is no longer so dependent on "pop culture" as a means of exposure to something "new" or "innovative," where we don't have to sit through hours of Peter Gabriel and Cyndi Lauper music videos, hoping something by NWA will pop up on MTV, or where hearing something outside the same 7 songs the radio is such a jarring experience that we almost have to like the new member of the rotation by default. This is probably why the music industry is having a bit of a difficult time as well. With such a wider accessibility to culture, a byproduct seems to be that the general public is growing more cognizant of the "pastiche" of pop. (That doesn't mean we can't enjoy that Bruno Mars song, though)