I think it's just the way I was raised. I don't like to hurt anything if I can avoid it. Obviously, if they are a danger to me, my pets or my family there is no question that the bug is done! If we see something in our home then I try my hardest to pick it up and actually put it back outside. Probably sounds strange to some people but I just see the bug having a family and so on... why kill it?
I will never just randomly step on a bug for no reason. I see a lot of people doing that. I guess just because they can?