Ok, first off...if you're willing to judge a womans desire (albeit romanticised) to be cared for in such a way as "tacky" etc., then man, you really don't get the female animal. Like, literally, you won't get one: in bed, in a relationship, into your life.
As for specificity, I don't think that's the case at all, I've known many, many women who have dated and married outside what they thought their "type" was. And as far as "what not to dos" go, its an internet dating site...they are trying to weed out the dorks, nutjobs, pansys, and psychos. So can you blame them for having some rules???
As for the bj versus knight analogy...I don't even have time to go into the massive explination it would take to describe how wrong that statment is...so I'll simplify: You're comparing apples to oranges...no, lima beans with that logic