The whole school was vying for his attention, it was nothing more than a competition so I can't blame Jaegu for not taking them seriously plus that he resented women at the time so them being popular and hot didn't mean anything for him. They definitely helped him grow as a person but he still had unresolved issues that were not sorted out so for them to want a romantic relationship with him was foolish on their part. As for DalDal, I just don't see anything genuine about her feelings for Jaegu, she seems obsessed to me. Jaegu has been obvious from day 1, that he was interested in Ingui and DalDal has always been aware of that. I don't find her behaviour appropriate, forcing kisses on someone who doesn't love you and barging in someone's home uninvited... that is not love or truly caring for someone in my eyes. She looks like she had still been stuck in competition mode... wanting to win Jaegu's affection to prove a point to her own vanity. As for Queen, while Jaegu was upfront about his romantic interest, she was the one who was beating around the bush for a long time. I agree with Jaegu that them having a relationship right now is just unrealistic, they bearly know enough about each other and the differences in their social standing is not someone two teenagers will be able to handle.
I think Jaegu wouldn't have cut ties with them if it had only been friendship that they wanted. He bowed to DalDal, showing that he does recognize and respect all she's done for him but lets be honest, if he softly rejected, she would have ignored him as she usually does and barge into his life again.
Jaegu is far from perfect but the girls put themselves in that miserable position, Jaegu didn't ask for anything from them, they did things for him out of their own free will so I don't see how all this is Jaegu's fault. Besides I don't think they are mature enough to handle a relationship since they act like immature brats to anyone showing interest to Jaegu.
This hate for Jaegu looks unjustified to me, one-sidedly pointing out Jaegu's mistakes while painting the girls, especially DalDal as poor victims when they largely contributed to their own misery.