On the political compass, and in general, there is a trend towards social authoritarianism. Why is this?
Society HAS ALWAYS BEEN TRENDING TOWARD SOCIAL AUTHORITARIANISM, it's just that some people are less authoritarian than others (but those people are a very minute few).
It's the way of the world Winston, it sucks mightily but until the influences of traditionalism wear off most people will naturally incline towards certain authoritarianistic elements.
I would venture a guess that society (American society, at least) is less socially authoritarian now than it was in the 1950s. There might be something to saying that there is a long-term trend towards social authoritarianism, but that does not really bear out as a strictly increasing function.