I'm quite acutely aware, usually, that a person might be feeling uncomfortable because I'm being aloof towards them, though they've done me no harm and don't deserve this treatment, so I can't help but loosen up and be a bit more uh, welcoming (if that's the word - warm, maybe?) toward them.
I'm not a mug, by any means. I'm not saying I give my bank details to anyone that just hasn't done me any harm (yet?)... I'm just saying that for me, as a person who considers treating people with respect and being generally accommodating, to be a thing that comes from my own self-respect, it was quite difficult to get my head around the way of thinking you describe, and to stop seeing it as a sign of a negative and self-righteous person.