
They didn’t turn a blind eye to anything. Why are people misreading the situation and so quick to judge? Hajin’s memories of Sihyeons past are incomplete, so Hajin at times isn’t a completely accurate narrator. And the members were shown to be concerned and try to help Sihyeon, who pushed them away. Because of how Sihyeon was in the past, they didn’t know how to help him after he pushed them away and they regret not being able to do anything, which is why after his accident and Hajin takes over his body with few memories of Sihyeons past, the members become protective of Sihyeon. Thy don’t want him to regain the hurtful memories and they don’t want him to end up depressed and cold again.

We saw for now at least two of them going through hard times in the past and for both of them Sihyeon was there to help even if they initially pushed him away, because that's how Sihyeon was when people he cared about were hurting, he didn't give up. Now we know there's at least one who knew even more than what we thought about Sihyeon's situation and the only thing he did after that was literally avoiding him and you're saying he didn't turn a blind eye ? Sure
I still don't know what to feel to Sanyu and Uihyun. They turned a blind eye when Sihyeon was falling apart and now, they want to play the knight in shining armor. Nahh. I like Rabun and Chan.