>the purpose isn't just infidelity as the article would have you believe.
The article states "The clients are often people who live at home with their parents and just need some privacy." Still, they don't clarify this any further so your explanation is useful. As it happens, a similar situation to what you describe in Korea is also common in Japan.
As the author points out, song structure biases the results, so that artists with structured and repeated lyrics end up with a lower "vocabulary". Wouldn't it make sense to simply combine repeated lines before counting? So you'd be measuring vocabulary in first 35,000 non-structurally-repeating lyrics.
For some reason, dirty names are common practice in audio tools. Some examples: "Rectal Anarchy" is another vocal synth for Buzz, grANALizer (emphasis not mine) is a popular granular audio effect, and even in the commercial world, it gets more subtle but it still exists: Image Line sells a plugin called "Gross Beat", which is a bilingual en/fr dirty joke.
The article states "The clients are often people who live at home with their parents and just need some privacy." Still, they don't clarify this any further so your explanation is useful. As it happens, a similar situation to what you describe in Korea is also common in Japan.