Hell, it's more fundamental than that: real CSIs don't solve murders! They don't talk to suspects, they don't take the lead in an investigation, they almost never venture out of the lab except when they go to the crime scene. I don't mind a show that glorifies the lab rats, but I do find it frustrating that they feel the need to also give them the roles the detectives are supposed to have.
Also, you ask any detective, a case is almost never made in the lab. It's supplemented by lab work, absolutely, and ideally you want both physical evidence and a confession, but lab work alone rarely puts cases down.