Do you think "Christians" would still celebrate holidays if they knew their origins?

Well, it's not as if we don't know. I was raised attending Christian schools. In the very early grades, we were taught about the pre-Christian roots of many Christian holidays, such as Christmas, Easter, St. Valentine's Day and more. It would be hard to find a Christian who wasn't aware of these origins. Today, we often celebrate these holidays for different reasons than our Pagan friends, but we do still observe them. There are a few Evangelicals who refuse to celebrate them, but for the most part, they're still on the liturgical calendar.