Why do reenactments have to be so cheesy?

I am watching a bad reinactment of a murder on the ID, Investigative Discovery, channel. It’s the story of a woman who becomes an FBI informant and has a relationship with the FBI agent.

This show is told from the perspective of the victim. It’s an interesting concept, not completely original, but a good idea. 

My question is,  why does the acting have to be so cheesy?