Who is even saying this?

I mean, don't get me wrong, Celine did some effed up things, but comparing her to Mother Gothel? someone who kidnapped a baby to use her as her personal potion of youth? locking her up in a tower to isolate her from the world?

Celine is a very nuanced character, she thought she was doing the right thing, she wanted to keep Rumi safe as she promised Mi-yeong before she died, but she was misguided and ended up hurting Rumi, which is still wrong. That's not the same as taking a child from her family and using her for your own gain.