Who were they wanting Jesus to hook up with? Paige Turco?
Who knows. There's a strong contingent for Carter/Reese, and Reese/Finch (even though both have proven Heterosexual tendencies). They seem to hide these truths behind the "More Shaw = Less Carter/Fusco" and yeah, it's possible/probable that Fusco might not have much time left. Which is fine, because this show doesn't have the "forever and ever" feel to it.
There are consequences, and Fusco's history will catch up to him, more than Reese's would (Government tried to kill Reese, but Reese was never a public figure, unlike a crooked cop). Carter is unfortunately stuck in bind, with HR trying to get rid of her, and her getting involved with Elias. But this situation can be fixed (odds are, with Fusco being the one to fix it, but at the cost of his freedom/life)
Haters also feel that she adds nothing to the core 4's specialties. Reese is already the muscle, Fusco and Carter have the sarcastic/snarkiness, and Carter has the female perspective. They didn't even see a reason for her to be in God Mode. I mean, that Jessica scene doesn't happen without her. It'd be a stare at a picture, a musical chord "flashback", and that'd be it. John needed someone to talk to as he discovered the location of the machine, and that couldn't be Carter/Fusco (not without letting them know about T.M.)
To me, she adds another muscle that further insulates Finch (cause hey, I want him living to get back with Grace dammit), and adds more potential backstory layers, as we don't know much about her, while we know a good bit of Reese and Finch's backstory. Also, if she can change from her Kara-like disconnect from humanity or not. And how she interacts with Carter/Fusco/Leon/Zoe (hoping those 2 will be back some, though both have new shows coming up)