I mean, think about oral sex alone. Doing that for someone who you have zero attraction or attachment to? Ew. But with someone you care for/are attracted to? Suddenly we disregard the "ew" factor and it's pleasant.
I've never understood why most girls I were friends with back in the day would perform oral before considering having sex with someone random. I have always viewed oral as extremely personal, I would have sex sooner than I would give oral. I am putting my face around a area that releases WASTES on a daily basis, and I'm putting one of the "instruments of waste removal" into my MOUTH.
I think it's because (at least in America) oral sex is kind of made a go-around. You can do it and still be a virgin, it doesn't really count, etc. When I think of oral sex, I think of the discussions we had in HS Sex Ed (what a joke) that basically encouraged oral sex as an alternative to actual intercourse. They'd never come out and say it but there was always this "Well, you can do THESE things and you WON'T have as much a chance to get pregnant if you do!"
Weird, I know, and I feel the same as you, but that's a definite factor. Plus, you consider the mainstreaming of oral sex (Clinton, it's used as a gag in American Pie, etc.) and it's become a less-threatening option in a lot of ways, especially when virginity is so prized, but sexuality is still thrust in our faces. Like I said, this is a purely American perspective, although mine isn't that of the typical American.