I don't believe (at least not in the generality you seem to be implying) that "we choose our standards because we want to win and they help us do that". We often arrive at our standards by means that I at least wouldn't call choice; those standards themselves determine what we count as winning; many people have found that their standards often get in the way of winning. (See, e.g., http://dreamsongs.net/Files/PoemADay.pdf .)