Which he argues is really down to the fact that "music is no longer the driver of a youth culture which in itself no longer seems to have any inherent, coherent sense of direction", which he further relates to "the process that affects all physical and biological phenomena on Planet Earth, which is the process of entropification - the natural movement to a state of randomness and disorder."
He wonders if the concept of entropy figures in Retromania, and it does, if somewhat shifted in emphasis, as hyper-stasis. But unlike Phil's great description of cultural entropy as "a voidal stasis in which endless diversity is experienced as uniform blandness" the difference here is the hyper-ness: the roil of micro-genres that keep emerging but never quite take-off (but equally, never go away completely... instead they rise and dip away and rise again (look at black metal's serial ascents to prominence across 20 years of existence, or the strange trajectory of grime).
One of the few 21st Century candidates when it comes to linearity in the old fashioned sense (musical evolution, audience expansion, crossover into unconquered territories) is dubstep. The original fans of course see the path taken by the sound through wobble into brostep as a devolution. But (c.f. rave>jungle and techno>gabba in the 90s, or indeed the history of metal itself), devolution is still a form of linearity.
Bass-tardisation is a direction. In this case (brostep), it is also -- as a centripetal, scene-forming/genre-conforming drive -- a force working against entropy. In favour of massification. Just look at the scale of the raves in America now.
This is a New Thing that is selling (but it's selling tickets, not records).
It also seems to be serving as the locus of generational identity. Whether any content will emerge beyond "let's go crazy" and "the parents will find this incomprehensible" is yet to be seen.