Hmmm... You mentioned in one of your tags Jack being terribly written. Is it the whole "I was being experimented on and all that stuff so I am an axe crazy and willing to blow everything up because edgy!!!!" thing?
Well, yeah, in part. It’s because she’s a confused mess of Broken Bird/Bad Girl tropes and you can’t complete her emotional arc at all unless you’re going for a romance with a Male Shepard. Her being kind of wonked due to trauma is not the problem (because people do actually end up wonked from trauma), the problem is how dismissive and sexist the treatment of that trauma is.
Actually I think the part of her arc where she was experimented on, and her catharsis coming from realising that she got off easy compared to the other kids, and that her survival was tied more to luck and circumstance than she thought was a great moment. And then she goes back to telling you to fuck off if you’re trying to make friends with her, and will only ever change her tone if a ~man~ doggedly pursues her and heals her emotional trauma with ~love~.
Like, all of Mass Effect 2′s characters are broadly drawn, and outside of Jacob, I think most of them get at least one interesting thing done with them. But Jack is horribly sexist and ableist and horribly wasteful for a character who already had very little going for her in the first place.