Just personality and sex? Jeez, so much for communication, love, adventure, and other traits that make a relationship "awesome."
It's not silly to have a sexless relationship. It just means they want to wait and see if the relationship matures into something serious. And if it does? Congrats!
I started dating my boyfriend a few weeks before he came to visit me for the first time. So I already liked him a lot to begin with; and yeah, he has a great personality. But when he visited me that first time, I didn't jump straight into sex. Hell, we've been dating for year and we still haven't had sex (granted we do tons of other stuff, but not the home run yet). Am I going to have sex with him? Well, I feel this relationship has grown a lot over the year and I've BEEN ready, so yes.
So, while I do agree that sex is important, it shouldn't be number one on the person's wants in a relationship. Especially in the whole "online dating" category; I mean, if people seriously say no to a boy/girl they like simply because they're not going to get sex out of it is: 1) dumb because you should AT least give the relationship a chance, and 2) makes you look like a douche bag because all you want to get is sex out of it.