It's simple most hate ML since he didn't fall instantly inlove with FL bow down to her and worship her, that's why they ship her with the aide who fell instantly inlove without knowing anything about her, most readers self insert too much and feel offended if the ML isn't all over the FL, why? Because FL is perfect and everyone should worship her same reason they tend to hate any other women who don't instantly worship FL.
that’s true, but it’s Fl herself that wants Ml so ┑( ̄Д  ̄)┍ but hatred is something that can change, sure there can still be a bit of lack in terms of trust when it comes to the sister but hatred can vanish as long as the person is willingly able to apologize n change and fully acknowledge their mistake!

I don’t get the hate for ML, his actions are valid