It's not ALWAYS because of that, her "taking Paulo's side" was a genuine concern for both Paulo's health and worried about Abbey's self-control. (It' also why Abbey is ALSO on the fault for immediately lashing out and leaving because he sees everything as Good Guys vs Bad Guys).
However, this could have been avoided if she had been mroe honest about explaining both sides. Again, is not like she thinks with her "dick" all the time, but rather her constant need for "everything to never be wrong" leads for her to just push things under the rug rather than confront them.
Abbey dump her because the reality is that, yes, she'd have still drop Abbey like its hot if it meant being with Mike. Paulo had to force them back together and she didn't really object it, which led to more volatile emotion bottled up that erupted in the Chokening.
My point is that Daisy is not the worst for actually being intentionally a jerk, but rather than she lacks the self-awareness to realise her lack of action only makes things worse, and we are suppose to accept it cause Taeshi never shows Daisy in a negative light. She is always the "Pure Hearted one who does not wrong."