1. Some workplaces use English names (and even English language) so co-workers can speak/refer to each other without using the social hierarchy constructs built into the Korean language.
2. Social (partnered) dance clubs go by nicknames for the same reason. Even though I dance with them on a regular basis, I don't know most of my dance friends' real names. I'm not aware of any other country where dancers do this.
That's so interesting. It reminds me very vaguely of Indians escaping the caste hierarchy by converting to Islam or Buddhism. Sometimes the easiest way out of a restrictive system in your culture is just to switch cultural contexts entirely.
The funny part of the Kakao CEO asking to be called Brian is that there was a K-drama (Search WWW) with a fictional tech company, but they also made the CEO name Brian. I suspect if this idea had gone on every CEO would be called Brian.
This is intended but didn't work as such, because wording only constitutes a small part of the whole social hierarchy.