wait actually I want to explore the "Isaac Rossum creates Roberta in the image of Lyla Grunt after accidentally killing her" thing some more. Maybe he became obsessed with tracking the investigation (or lack there of) of her disappearance, first to ensure that he wasn't suspected, then out of morbid curiosity about the kind of person that she was. Maybe from there he develops some kind of parasocial relationship with this dead woman and that inspires him to build Roberta, or maybe he can't stop thinking about her family and deludes himself into believing he can bring her, or at least some part of her, back to them and that is what inspires him to build Roberta. And it's only afterwards that he grows attached to her and decides to keep her with him.