Why does Kakao disable accounts?

Kakao's policy on account inactivity was implemented in accordance with the Expiration System of Personal Information, under which personal information of long-time inactive users are discarded or stored safely to minimize the storage of unnecessary personal information and to reduce the risk of leakage. 

Personal information is to be discarded or stored safely after one year of inactivity pursuant to Article 16 of the Enforcement Decree of the Act on Promotion of Information and Communications Network Utilization and Information Protection, Etc.