I'd just like to start off with the angry part first- Women are not property. They can not be compared to cars or inanimate objects. That is offensive, rude and very mean. I don't care if I'd be considered a new car or a used care no woman wants to be compared to anything like that- ever.
Now, with that out of the way-
Not all guys want virgins, plain and simple. For those that do, provided they are virgins themselves they can be that restrictive and go them for waiting. If they have sex and then expect a virgin then, well, they can go f*** themselves because that's just not fair. Oh yes well I can have as much sex as I want but I will only date girls who are virgins. Well then you're just f***ing all those virgins, dumping them, ruining that special moment for someone else and living a complete contradiction.
As to why people should want to date women who have had sex, well because it's not about what you've done. it's about who you are. Any one who judges women solely based on their sexual activity (or lack there of) is petty. Yes it's okay to take that into consideration when dating a girl but not all sexually active girls are the same.
Every one has a different view on sex and just because your opinion is that it's only for marriage doesn't mean it's everyone's. I think sex is a natural thing, I think it's a beautiful thing that two (or more) people can share with each other and it's open to interpretation. Sex is like art, there is no one right or wrong answer about what a piece of work means. Even if the artist had something in mind it doesn't matter because the piece speaks to each person differently and invokes different emotions in every one. To deny their interpretation or to say it's wrong is to deny what they feel. You can't reject emotions, it doesn't work like that. That is a believe, an emotion and it's there so it's real.
You believe that sex is sacred, so there's one correct interpretation. But there are people who believe sex is for when you've determined you love someone and want to show them, and they're right, too because that's a valid emotion/feeling to have. No one handles things exactly the same. There are people who have casual sex, there are people who don't. Just like there are people who cry at funerals and people who don't. There are also people who are spiritually virgin, and chaste and who accept that as just as good as physically virgin.
So people look for partners who share the same sexual values as they do. And not every one things of women who have had sex as "damaged goods". You may think that but not everyone does. I think you need to really calm down about it. Just because women are sexually active doesn't make them bad people, or lesser people. It's just a different lifestyle, and we all need to be accepting of everyone's lifestyles.
Here, you might like to hear this guy's opinion on the subject: