...because he doesn't regret what he did. If it resulted in Min gaining the power, connections, and money to protect Cheol—and allowed Cheol to break free from his father—then it means the events of 14 years ago were worth it. Min knows he hurt Cheol, but there was no other way.
What's the point of having him when you literally won't apologize because you don't feel guilty about it?
Ykw forget the happy ending let me get the bad ending where one of them does die and let it be cheol too cuz hell no