...and appreciate the work of progressive Christians. That's not what's in question.

I even understand Jesus saying "Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil" afterall, he was a Jew.

But the Ten Commandments are part of the covenant of the Jews. It's not a Christian obligation to follow. So what is the conservative Christian explanation for emphasizing the Ten Commandments so much? Perhaps the "Jesus Seminar" you mentioned has a FAQ about these issues somewhere.