It was illegal for a long time in many Asian countries such as Japan for a woman's genitalia to show, so in p*rn and stuff like that they'd have the woman have a lot of hair so that her privates wouldn't show. The rule was the same for men, so that's why tentacle p*rn is around. They couldn't show a penis, so they had tentacles instead. In Hentai they would either have girls with LOTS of hair, or they'd be wearing panties.
Personally I shave because it seems cleaner to me somehow. My girlfriends tend to agree, maybe we're just paranoid about smelling bad or something. But personally, when I go to the bathroom I know I'm clean after. I would think that a girl with a lot of hair would get their pubic hair soaked with urine and they'd smell bad. I don't think it would matter if you showered everyday or not, because if you shower at the beginning of the day, you're still going to the bathroom throughout the day. It's the same with underarm hair, girls I knew that didn't shave their arms always smelt bad even though they showered a lot. Hair holds onto moisture, that's just a fact, and if that moisture happens to be sweat, or urine it's going to be there all day until you shower. I think that's gross.
As for Asian girls not shaving, based on the girls I know, I'd have to say that's probably true. I'm sure there are Asian girls that shave, but all the East Asian girls I've known throughout the years have always insisted on wearing shorts to the beach, and they've said it's because they don't shave down there and regular swimsuits show the hair. Also got into an awkward conversation with one Asian friend asking for a tampon, I said I only use pads, she said that she hated them because they stick to her pubic hair...I just said I don't have that problem.
So to the people saying that girls that shave are "slutty", I've shaved since I was 12. I certainly was not "slutty" at 12, and I'm not now. It's called hygiene, and I'm certainly not going to be caught walking around smelling like p*ss just because some pig thinks a hairy vagina is "innocent". In my experience, people who dig lots of hair on women are usually creeps, and I keep them at a sizable distance from myself.