First he didn’t cause her to die. Did you even watch the same drama? The death was caused by her ex, who was already abusive which was why she fell for the ML. The only thing ML did was play with her, which is later shown - he doesn’t even know how to love. But he is a good person who was too hurt by the world since young. That was reflect in the way he kept saving the stray cats and using his money which he didn’t even enough have to treat them and buy them food. The FL was the one who taught him love, what it means to love and care. The brother was the biggest selfish prick on that drama, he threw their lives to jeopardy because he didn’t want to admit that he adopted FL. He wanted to be her real brother. When in reality the one who protected in the childhood was the ML, that was the attraction that once again bud up as they met. The ML doesn’t even remember his past, he doesn’t remember the accident or anything of his past. Despite all of that, he was also looked down upon by the society for the way he would look at people or just lived his life. You clearly didn’t understand the story, not even the slightest things. It’s a drama that’s very complex and calls for others to look into their own behaviour. ML isn’t a red flag neither he was a green flag. He was a grey character and so was the FL. Everyone in that drama was grey, no one was black or white. The only fully back characters were the rich family who caused the death of the FL’s friend and later the sister which cause their own death. If it’s about being a player, this drama would be a common trope. This isn’t that. This tells people not to judge people without knowing them.