Most of the criticism I've seen seems to come from people who don't seem to understand how translation works. I have no idea how accurate the subtitling is, but the job of a translator isn't to word-for-word translate the text but to choose words and idioms that work best in the target language within the constraints of the display. Subtitles are usually more faithful than dubs because dubbed translations need to match not only the sense but also something close to the timing of the original speech, whereas subtitles just have to be short enough to read comfortably in time.
One example was that the literal translation was "boss" whereas the subtitle used "sir". Well, okay, but using the word "boss" like that carries very different connotations in the English-speaking world's low formality culture and in Korea's high formality culture so the word "sir" sounds more natural and better expresses the intent. Another example is the word "babe" which was apparently literally translated as "older brother", you call someone you're boinking "older brother" in English and it sounds ultra-creepy. I'm assuming - contextually - that it doesn't have that same connotation in Korean.