The sad truth is, watching the general fandom (fandoms in general for that matter) ... its easier said than done. This is especially true when you have instances like this, where the character who is harder to relate to (because their pain and trauma is less common) is causing pain to the one an audience member does relate to; and thus empathizes ... and even "self-inserts" with. Thus, the issue of lack of empathy and an unwillingness to understand that harder to relate to character compounds.

A simple example of this factor is simply Adora's requests for Catra to leave the Horde. If you relate to Adora, then Catra "throwing away the chances Adora was giving her" must come off as awful. However, if you look back and understand HOW Adora was requesting Catra leave ... you'd get why those attempts were unlikely to work. How presenting Catra with functionally opportunities to abandon everything she'd ever known to join Adora on HER journey ... were liable to rub the wrong way.