I'm not blaming people who find Nia unbereable. Truth of the matter is we are all different, and there's people who have less tolerance to others' 'special personalities'. An example of this is Nika himself, if it wasn't for Nami being the voice of reason,he would have gotten rid of Nia right away and wouldn't feel sorry about being mean to her.
I personally learnt to pay attention to people's words, reactions and body language, no matter how insignificant their actions are (perks of dating a psychologist for while, among other personal things), so whenever I met someone in real life or see some character who seems annoying at first, I hold my judgement and wait to see more about them. I see in Nia more than it meets the eye because I'm patient enough to she past through her annoying initial behavior, and while she isn't my no. 1 girl in SG, she's in the top 3 because of this very reason. Besides, I trust Ocean's character development and storytelling, can't wait to know more about her.