Because, as Kolton told Parade, "There are things that are extremely interesting other than money in our relationship."

Katie isn't particularly interested in talking about her bank account, either. 

"I knew that the finances were a portion of [the show], but I didn’t realize that it was quite so money driven, really, until we started filming," she told Parade. "Had I known that, I definitely wouldn’t have agreed to it, just because [money] is not something that I'm that excited to talk about in my everyday life."