I think that Kreia's attitude was summed up quite early on, to paraphrase: the true battle exists within the hearts of every self-aware being.
She wanted the choices, whether creative (light side) or destructive (dark side), to be truly of the being.. and NOT part of some grand scheme of the Force.
To branch off into the idea that the Force is pretty awful in some ways:
I saw this right off after seeing Episode I.. the 'balance' of the Force is not the wholesome thing the Jedi likely assume it to be.. in essence.. by Episode IV's time.. the Force *has* become balanced with Vader's help, by having four main powers in the galaxy: Vader, Obi-Wan, the Emperor, and Luke. Two light, two dark.. but having one light be eliminated by New Hope's end means that one of the dark side will have to be gone.
Inbetween Episode I to IV, hundreds, if not thousands, of Jedi Knights were killed to bring this balance. Was the Force the reason? Or was it choice? Or both?
In essence, Kreia was railing against Fate. The mistress of Betrayals and Manipulation could not have even the Force manipulating her, it being too unbearable. Yet ironically enough, the Force probably wanted her to help the Exile all along.