You know not all CDMA carriers are iPhone partners, right? It's not like GSM. You cannot simply connect to their network, they need to be able to program your phone, and only partners can do that.
Weird how under South Korea, only LG telecom is listed as CDMA, because SK telecom does use CDMA but also uses UMTS 2100, while KTF (Olleh)uses UMTS 2100. UMTS = WCDMA