Why do people want to ban the 10 commandments from courthouses etc?

I know they come from the Old Testament but they are universal values that most people teach their children. Only Atheists would not like the first commandment, but if you don't believe in God what difference would the first one make to you. All in all I think the 10 commandments should be embraced. It is nice to have some of these things in our courthouses etc. We will never be able to replace it in this day and age because everyone is so open minded they stand for everything and nothing , so no decision ever gets made. What do you think?