Sex is a very important part of a romantic relationship.
The physical attraction and sexual activities, and such, that go on are what seperate romance from just friendship.
I also think that people cheapen sex too much. They say that something is "just sex" or all someone thinks about is "just sex." I do agree that a relationship can't only be based around physical attraction and lust, but I think that those things are an important part of any romantic relationship.
Sex is the ultimate physical way to show your love to your partner, it is the culmination of all those words that aren't quite right to show them how you feel. Sex is beautiful and wonderful and amazing. Sex is not just some carnal, physical activity that we do to survive or we do because we're horny. If that's what it is to you then you're doing it wrong, or with the wrong person.
I'm sure some people will disagree with me, but this is my opinion and how I feel about it. I wouldn't be able to survive in a sexless marriage, I think it would just seem so empty.