It is rare to find women who don't like it, but they do exist.
I agree. But I will say we can mistake those who "don't like it" as those who hate it in general. I know with some gals, they're not fans of it -- but doing that is "too much". Once in a good while, I'd be befuddled by a gal who puts oral sex as "home plate" and intercourse as "3rd base".
As far as oral sex on a girl doing nothing for her -- I think there's more about it than that. Like a negative association with it ("ewww") combined with it never doing anything for her to overcome that. If it was truly just a "does nothing for me", then it'd be like sucking on an index finger. "Sure Jimmy, go ahead, but, it does nothing for me. If you got some special tactics to try out, feel free. I'll keep watching TV..."