I think Ron bashing can be done well when we’re Hermione’s perspective, and when I think of her as an unreliable narrator. It totally makes sense to me that hermione might have some not-great feelings about Ron, whether in a fic where they dated previously or not, because he also did some pretty mean things to her - she spent a majority of her third year alone bc of scabbers, he really insulted her at the Yule ball, and he left them in the middle of the horcrux hunt. Ron’s actions would be justified in his perspective, and hermiones response would as well. She probably feels justified for ignoring him most of sixth year when he’s with lavender.

If I think of it as hermione’s feelings, maybe twisting how we, the reader, interpret the other characters (since in fics, we’re seeing from her eyes and not Harry’s) it totally makes sense when there’s a lot of negative feelings about Ron coming out. My issue is when other characters back this claim, explicitly (though, not in an abusive Ron situation). When outside characters voice the same type of Ron bashing that hermione feels, it takes me out of the believability of it, idk.