Brennan

Sweets describes her as being "INSENSITIVE and EMOTIONALLY CRUEL."

And he says that's due to her "Childhood Trama" issues of having been "Abused & Abandoned," which he explains is the reason why she uses her "INTELLECT as ARMOR" or as a way to protect herself from INTENSE EMOTION like LOVE.

In other words, it's also the reason why she rejects BOOTH when he tells her that he loves her, and then she PANICS in the "DOCTOR in the PHOTO" episode when she identifies with the other dead woman who rejected the pilot (for the same reason as Bones rejected Booth).

Then she also tells Booth that she LOVES him, but since he's already moved on with his life & is dating the reporter, he rejects Brennan.

Then the reporter turns down Booth (when he proposes to her), & he PANICS, & Brennan comes to his rescue, & the rest is history.

So NO, she isn't a bad actress, because she NAILS the ROLE that she portrays.

And the show also has a VERY HIGH RATING because it deserves it.