Why did/would you hate the movie, HK? Does it have anything to do with Jane's politics?
In the U.S. a LOT of people despise her and her movies because of the photo that was took of her in North Vietnam. I'm not sure how people in UK feel about her, but she doesn't get much love here.
Cat Ballou is a 60's comedy western. Which part of that description makes you think I'd like it?

I seem to remember singing, too. All too, too awful.
No, nothing to do with her politics at all. For me it was much as Christine said and, by the time I was of an age to know who she was, her movie career wasn't really a thing. Certainly not when compared to her fitness stuff. As I remember it, I knew she 'used' to be a movie star and now did these videos. Men liked her, but that seemed to be because she was in Barbarella and Klute. That's about all I knew about her.
I've never cared/bothered about what actors/actresses think in relation as to whether I like them or not. I don't care about/for her, though and, with the exception of The China Syndrome and On Golden Pond, I can't think of a film she's in that I'd care to see and haven't. For the most part, she just doesn't choose films I'm bothered about seeing.
Lee Marvin is in it too and, while I don't dislike him, he's never someone I'm pleased to see onscreen. Again, that's probably as much to do with his work choices as anything else.