I think BioWare writes some of the best characters in Western RPG's and some of the reasons people are giving for certain characters to be the "WORST CHARS EVAR" is basically just, "I don't like them for reasons and therefore they're bad". There are plenty of characters that I dislike but I wouldn't call them the worst characters ever. I guess it's to be expected, there's always so much negativity in threads about Bioware games.
KOTOR: I was very very young when I first played KOTOR so my opinions are a bit muddy. I guess I never really clicked with T3-M4 or Jolee Bindo because you recruited him so late in game. I also found Juhani straight up ugly so I never liked her.
Mass Effect: Usually, I rarely dislike a character, just oftentimes a character really won't click with me. For example, Kaidan, Thane, Jack (at first), Legion. Sometimes I would play and I would find myself really liking one of them for a playthrough only to play again and not care about them anymore. For some reason though, I've always disliked EDI as a squad member, maybe it's cuz I dislike robot characters hence me not giving a single fuck when Legion died but damn I just really think EDI is a waste of a squad slot, they definitely should have chosen someone else.
Dragon Age: Same goes for Dragon Age where I rarely straight up dislike characters, but I can't say I've cared much for Wynne or Oghren although I used Oghren more on my most recent playthrough and instead of being a boisterous dumb drunk he seems to also be a tortured character, and that's a depth I'd never seen before,, and I appreciate. I've never liked Fenris because he's just so Final Fantasy and I don't wanna sound like an MRA but he REEEEALLY seemed to be blatantly pandering to the female fans of DA and he just seems so out of place in the game, I dunno, call me crazy.