A character becoming kinder or falling in love doesn't undo the harm they've caused.
If the writers want the audience to sympathise with a character who has contributed to someone’s death, they need to do more than make that character lovable.
Most of these reviewers here seem like bandwagoners.
I thought he was doing a pretty good job made my blood boil and I’m 77 years old it left us with an Imagination…
After engaging a decent amount of time for this drama it felt like his acting was injustice for a strong male character.His voice is not that of manly,the dialogue delivery did not felt natural but on the other hand 2nd ML did a gr8 job
Second half of this drama is soo touching that it eventually fill my eyes with tears.Blessed with some of the best actors.It somewhat changed my perspective towards life,absolutely worth watching❤
K-Drama 
If the writers want the audience to sympathise with a character who has contributed to someone’s death, they need to do more than make that character lovable.
Most of these reviewers here seem like bandwagoners.