There's nothing wrong with Kristen Kreuk. It's how the Smallville showrunners treated her character like a goddess who could do no wrong that was the killjoy -- putting her in situations that don't make sense for her character because they don't know how to write for her but want her involved as much as possible, with outcomes that make no sense because they want her to come out smelling like roses.
Sort of like how the MALE head writers on General Hospital have a hard-on for Sonny Corinthos. They wanted the audience to be sad that he had lost his will to kill!!!