After reading the essay referring to genres and how it specifically addresses the different kinds of genres there are for music really caught my attention.
However whether we are discussing different genres of music, movies, literature, etc. there is always a case of using a genre to overgeneralize a specific thing.
The topic of music in the essay reminds me about a different "genre" of music I listen to that is often generalized. I am a big fan of hardcore music - a genre often called "screamo" - by those who don't understand the music. Within the term "screamo" there lies multiple sub-genres that have actual names rather than an overgeneralized statement such as "screamo", and within that sub-genre to hardcore, is an entirely different culture than the other remaining sub-genres. A famous quote by a hardcore musician Derek Miller is, "screamo is a term that describes a thousand different genres."
To show the intensity of the overgeneralization, here is a condensed list of hardcore sub-genres:
Hardcore, christian hardcore, crossover thrash, punk, punk rock, deathcore, emo, electronicore, grindcore, hatecore, melodic hardcore, melodic metalcore, emo, metalcore, skacore, thrashcore, post-hardcore...
There's a lot more remaining, but this is just an example of the harm that genres can do to music, movies, literature, etc. When we put something into a genre, we generalize. Whether that's a good or bad thing is everyone's own opinion; but generalizing can do more damage than one thinks.
Once something is applied to a genre, a part of its unique aspects have been destroyed.