My parents are really conservative and always thought people should have sex only after getting married. I understand that having been their personal choice (and it's not like it was hard for them to wait when they got married when my mom was literally 20), but I don't agree about the aspect of them imposing it onto others, including their child. There are ways of encouraging someone to make a thoughtful decision about sex without restricting it to that.
I think my perspective just changed over time as I realized the importance of applying thoughtfulness to picking someone to date to begin with, but also recognized how high the divorce rate is. Seriously, is it really that big of a deal? I don't think so.
I'm personally kind of conservative myself in that regard. I don't do random hookups. But I'm also not waiting until I get married, are you kidding me?