Isha
Depends on which way one wishes to look at it. By not disclosing everyone about oneself to a partner, could it not be said that that is akin to dictating terms? Say I enter a relationship, and choose not to disclose certain aspects about myself. Am I not dictating how much of myself I am choosing to disclose to my partner?
As for walking away, yes of course that is an option, but at what cost. What exactly is the person who can't "abide by it" losing when he/she finds out something about their partner that changes the relationship and perception of the person that they thought they knew? Or rather, changes the perception of their partner that their partner expressed to them throughout their time together?
Any partner who walks away, I doubt that they have ever done so without regret, without a heavy heart, and without wishing that it would have worked out. No one goes into a relationship thinking about the day it will end after all.