The 73-year-old star, who appeared in the motel-based TV soap between 1978 and 1985, and then again when it was relaunched in the summer, recently announced that she was leaving the four-day-a-week programme and returning to Last Of The Summer Wine, which is filmed in the Holme Valley.
Central TV put her decision down to the long hours demanded by Crossroads.
But in a religious programme recorded for Granada TV, Kathy, a committed Christian, discloses that the real reason behind her departure were the racy plots which had been developed in the daytime show.
Kathy, who plans to return as Nora Batty in Last Of The Summer Wine, said: "It wasn't the Crossroads I was in originally.
"That was a really happy family show and anybody could watch.
"I was a bit disappointed when I got in and saw the scripts and the storylines," said Kathy.
"You've got a girl of 16 pregnant right away and, I mean, she didn't really know who the father was, which makes it even worse."
She said many scenes in the programme were "sex for the sake of sex", which she could not agree with.
In the programme My Favourite Hymns Kathy says she often felt relieved that she was reaching the end of her television career.
She believed viewers were often influenced by the way they saw actors behave on screen.
Broadcasters were not always as responsible as they should be, she added.
"We've got to protect children and let them watch what is good for them to watch, until they get to a certain age."
A spokesman for Crossroads said: "We understood she was leaving as a regular because she did not want to do the demanding hours required.
"She has never said anything to us about being unhappy with the storylines and has always been very supportive of the show."
The spokesman added: "We are doing a soap for today, and some of the storylines would not have been seen as appropriate 20 or 30 years ago.
"But we are huge fans of Kathy and will always welcome her back when storylines allow."
My Favourite Hymns will be on Sunday, February 24.