I want to clarify if my perception of systematic differences between Je'daii and Jedi in terms of Force balance and related religio-cultural (religious/cultural) differences is accurate and, if so, why the Jedi chose to take their Order in a more extremist direction.
When reading books and watching the movies involving Jedi from the time of Darth Bane to the New Republic, it always seemed to me that they pay lip-service to "balance" of the Force, while actually pursuing only the light side (Ashla).
Jedi attempt to free themselves of all emotion and attachments, seeking peace.
There is no emotion, there is peace...
There is no passion, there is serenity...
-- Excerpts from the Jedi code (emphasis added)
They seem to react negatively to any trace of the dark side and I can't think of an instance when Yoda or Obiwan channeled dark side energies for any reason. This Puritanism seems to be reflected in Jedi culture, such as the custom of not having a spouse / lover, being estranged from one's parents since childhood, etc.
The ancient Je'daii on the other hand seem to actually believe in balance. They played roles as peace keepers and seemed the overall champions of light, like the Jedi, but unlike the Jedi they taught that too much light (Ashla) was equally as dangerous as too much dark (Bogan), as mentioned in Dawn of the Jedi. Je'daii such as Lanoree Brock and her masters called upon the dark side at times, such as to extend Lanoree's life through alchemy of the flesh, or to aid in battle when vanquishing a foe.
Be a prisoner of neither Bogan nor Ashla. Strive to live in balance.
-- Je'daii Temple Master Ketu
The Je'daii's culture seemed to also take more of a middle path. While they clearly put their roles as Je'daii above other aspects of their lives, they could marry, have children, and visit their parents.
So, why did the Jedi chose to take their Order in a more extremist direction?