I undersand what you are saying. But Jesus taught HIS disciples that most of what the Jews of HIS day were teaching (especially what the scribes, Pharisee's and saducee's taught) was wrong. They were teaching tradition instead of truth. Are we as you say supposed to build on that ! If we did we would crucify Jesus again and again for time immemorial. When was the last time they got it right ? Did they ever get it right ? Well I supose we can learn from their mistakes, if that were ever possible as history shows we never do.
Just a few idea's to throw in the pan for your consideration.
Col 2:8 -10 Beware lest anyone cheat you through philosophy and empty deceit, according to the tradition of men, according to the basic principles of the world, and not according to Christ. For in Him dwells all the fullness of the Godhead bodily; and you are complete in Him, who is the head of all principality and power.