Nothing against Dobson, but Bundy told Dobson everything Dobson wanted to hear, so Dobson believed it.
Or, he told Dobson the truth.
Why lie on death row?
Bundy didn't pin his predilection on pornography; he pinned it on, specifically, VIOLENT pornography. Which goes along with the "addiction view" that some need more and more thrills once they become numb to a certain level of violence. Rape being a combination of lust and power...