Responses
It's not that Irene doesn't like/love him. She poured all her heart onto Ciel in their past life, and you can't simply erase such strong feelings at will. Heart doesn't work like that.
I don't think she ever stopped loving him. Rather, she gained self-respect and self-awareness after being truly loved and cared for by her family, and that's why Irene didn't (initially) want to get back with him. But alas, a romance webtoon will follow its fated course...
FL is in denial phase. She said she doesn't love him anymore, but she opens her heart when he shows his desperate love for her.
Now I get the reason of the readers' frustration over her.
Irene, if you don't like Ciel in your life anymore, don't give him any more reasons to put his hopes up okay? However, it's so obvious they still like each other.
Their current status: Loves each other, but NO LABEL.
Ciel, on the other hand, became a 360° person of what he used to be on the first timeline. He now openly shows different emotions in front of Irene. He can't live without her, and respect her decisions— which is a good character development, BUT!! The trauma he gave to Irene on the 1st timeline will not be forgotten & forgiven so easily.
Well, they're both... frustrating & complicated persons. Hence, the reason why they're the main leads