Whether actively seeking truth or having truth thrust upon you is irrelevant, the act of ignoring and dismissing truth is a negative act as in the same when withholding the truth if it should be told. I think this is primarily why humans are negative oriented beings- lack of truth, which is knowledge.
But then one has to think about positive and negative and what one means when speaking those words. What do you mean by positive and negative?.
I concur that truth is probably one of those sacred things one should aim at, whenever possible, in most situations, particularly in one's relationship with oneself, one's choices, and behavior and so on. Lying to oneself is detrimental to so much. In one's relationship to another, I do think that one ought to strive for truth, first within oneself and yes, with others.
Having said that, the dispensation of truth is also very context specific, there are things that would be harmful or cause distress, if delivered at the wrong time, to the wrong person, in the wrong context. There are things about me, and my life that I will not share with my coworkers for instance, or things I wouldn't say to a young child, that I would to an adult for instance. Am I withholding truth? or living negatively because of that choice? I don't think so personally.
Rather, I think, it's another layer of truth, the truth about the relationship, the context and the dynamics that govern those specific relationships, and what those situations ask for as an appropriate level of interaction, not every interaction requires all the truth all the time, that doesn't mean one has to lie, but being 100% forthcoming with everything could end up in harm, which would land one in a negative situation.
So, I do think that striving for truth is positive, in as most situations as possible (which also includes admitting when one isn't ready to learn the truth, interestingly), the dispensation of truth.. or the level of truth about some things, isn't as black and white and could end up being actually quite negative and self centered. Not every honest word is delivered because of a love for truth, and not every lie is delivered with the intent to destroy. It's very context specific, OSIT