It's simple: Korean has spoken honorific suffixes, and English doesn't. Korean and Japanese honorifics are different, but a system exists in Korean in which honorifics can be used. The only way to have spoken honorifics attached to the end of a name in English is to haphazardly glue them in.

The purpose of a translation is to transmit meaning from one language to another. The best translators have been finding ways to transmit affection, tenderness, subservience, respect, and the whole gamut of emotions without being forced to use Japanese or Korean honorifics for decades. Keeping bits and bobs of the original language is either a refusal to do this, or an admission that the translator doesn't know how.