In the US, there's a lot of cultural messaging about vaginas being gross. Feminine deodorizing sprays, scented pads and tampons, douches, etc - all that stuff is marketed like it's just an obvious fact that my pussy is naturally gross and I need to Do Something. If that attitude is reinforced by the people around you, it can be really hard to feel good about that whole area
I have known women who didn't masturbate (and didn't want anyone to perform cunnilingus on them!) because they didn't want to touch (and were afraid to let anyone stick their face near!) what they thought of as a gross area. It is really, really, incredibly fucking sad.