Fictional villains are usually cooler and more entertaining than the good guys.
Characters like Darth Vader, Cruella De Vil, or the Kurgan completely steal the show imo. BG also has a history of memorable villains - Sarevok (basically the Kurgan, heh) and Jon Irenicus were both great.
Similarly, I find playing a villain myself far more entertaining than playing a stupid goody two-shoes. I'm already constrained by a moral code IRL, I don't need that baggage in a game. Some NPC annoys me? I chunk them! Some fool wants me to retrieve his sword or whatever? I get it, then show it to the npc but keep it myself and laugh at them!
I'm really happy Larian gives lots of opportunities to be a selfish dick and outright evil. It's going to be so much FUN. With that said, I don't usually play
completely evil characters. It's more like, screwing people over because they deserve it (though the reasons for why they "deserve it" may be really flimsy). But I don't randomly kill npcs I haven't even talked to or torture animals or stuff like that, that's not fun to me.
