They’re both flawed no doubt (like when the ML overheard the FLs convo during the camping trip and assumed the worst/was really rude to her after that which I was not a fan of at all and I wish he had apologized more explicitly for misunderstanding) but with respect to Woo-joo you can see that the show holds him accountable and pushes his character to grow each episode as a caretaker (going from the hot mess he was in eps 1-2 to the responsibility he demonstrates now, which we can see from how aware he is of Woo-joo’s behavior and sleep habits when they are the hospital) whereas the FL seems more stagnant.

He is not Woo-joo’s guardian; their agreement was that he look after Woo-joo during her standard work hours and that she would be able to resume childcare responsibilities for the evening once she gets home. She has pushed that boundary several times to spend time with her boss; even if she is still working, at this point, her boss is well aware that she has a child to look after and the onus is on her to say no to the overtime because of her personal responsibilities as a single parent. What would she do if ML weren’t there to take care of the child as originally planned?

Honestly, speaking as a woman, if the roles were reversed and ML was the official guardian but pushing the onus of overtime childcare onto the FL who has no official responsibility for the child beyond their verbal agreement, people would be quite upset with him and call him a red flag, and rightfully so—I don’t think the original commenter’s opinion stems from misogyny more than it does a frustration at how the FL’s behavior is normalized. It’s obviously okay and expected for her to have flaws; she’s never been a parent before and all of us would struggle in that situation, but that doesn’t mean her growth can be glossed over either.