Actually found a pretty good source on what the Korean rules are (hint - it is about paid peering). This is somewhat biased (it's from a Spanish telecom - actually editing this again, the style choice + date formatting…
Because transit is expensive due to peering fees that Korean ISPs charge? Net Neutrality rules in 2015 did govern peering (but not nearly as much as other aspects of the internet).
Actually found a pretty good source on what the Korean rules are (hint - it is about paid peering). This is somewhat biased (it's from a Spanish telecom - actually editing this again, the style choice + date formatting…
Because transit is expensive due to peering fees that Korean ISPs charge? Net Neutrality rules in 2015 did govern peering (but not nearly as much as other aspects of the internet).