Something I rarely see specifically pointed out is that evil and whiny/nitpicky/annoying don't have to be linked. You can have evil characters that are a joy to have in your party. And even the "whiny" and critical ones can be likeable. I'd say most of BG1&2 evil cast was fun to play with. (Ok, not Eldath and Shar-Teel, though I know some people like the latter.) Edwin is an arrogant prick and he's generally liked. Montaron and Xzar are great.
Imo the problem with BG3 companions is that they (from what I gather reading this forum) act like the most stereotypical annoying girlfriend that criticizes every little thing you do in the most aggrevating way possible. (That on top of the "teenage melodrama" vibes.) My impression after reading the patch notes was the this was the issue that had been addressed, so I was surprised by the negative reaction.