the one-dimensional specist asshole with absolutely no other character trait.

I used to think that about Ashley until I did what I nicknamed my Asshole Run. I was an Adept, so I usually had Ashley and Tali around me. I ended up listening to their elevator conversations, and Ashley treated Tali a lot differently than she did Wrex or Garrus (the ones she saw as a military threat) - she warmed up to her and treated Tali like a little sister. So when Tali died in that run on 3, Ashley was gutted and was crying when you go talk to her afterwards. Seeing her actually have a character arc made me like her a lot more.