Sam, I don’t think he means that. The point is that when you get very technical with quotes from historian’s assumptions of attitudes of bygone days (while ignoring attitudes expressed explicitly in Seforim) and generalizations based on a context that is a product of similar background, it will be very far from the normal attitude of a regular Yid, who have a better tendecy to pick up the true nuances of attitude from the Mesora.
We don’t have a Mesora on details of Mitzvos. We base Halachos mostly on Sefarim. But, in Hashkafa and attitude the Mesora is strongest. It is still a Toras Chaim.