If you're a complete stranger and I greet you with "hows it going?" it's because I'm ready for and interested in an answer. I think it's fair to say most Americans are the same way. Unless they are bigoted or racist or have some other hangup like that, we are generally willing to give any stranger a first shot at becoming a friend and we are willing to be outwardly nice during that first encounter because we don't have any cultural hangups like "saving face", "machismo", "stiff upper lip" or any of that shit. We look at anything other than that expected initial politeness and openness as cowardly, mean, strange or antisocial depending on who its coming from and how they present themselves.

It's not at all unusual for an American to make a snap judgement on someone based on how they react to that first initial interaction. It's not uncommon at all for someone to shake hands and afterward say "Well, that guys an asshole!" It sets the tone for the whole relationship. First impressions count!