Tradition ought not to be the source of ANY doctrine.
I don't think something should be enshrined in teaching books just because the previous generation did it that way.
On the other hand, I have no problem studying history to see if one can match up the Bible with early church history and thereby demonstrate if or how a particular doctrine was being taught.
Can you buy into that?
The only official doctrine of the Undivided Church (and of the Orthodox Church today) regarding Virgin Mary is that she is the Mother of God (Theotokos). This was proclaimed as Church dogma in 431 at the Council of Ephesus.
There is not a single instance where she is officially referred to, 400 years after Christ died (5th century), as "ever-virgin" by the supreme body of the Church, individual authors' and Church Fathers' personal views notwithstanding.
"Tradition ought not to be the source of ANY doctrine."
But tradition, custom and convention are so comfortable and effortless. It allows the professionals to interpret for you and you don't have to think for yourself. No messy working out your salvation in fear and trembling. Just do what they say 'cause they know. Neet huh?