There's something about ideology -- any ideology -- that can take people teleologically to extremes. It seems to me that is primarily because ideology rests on abstraction and theory, which can deviate sharply from reality. Moreover, ideology tells us exactly how things should be, or rather, must be, for the true believer. We know that humans are rationalizing animals, so sometimes ideology can be an excuse for releasing our basest instincts. But often it just blinds people to the world around them and leads them to a path of callous and cruel behaviors.
We just don't live in a world of simple absolutes, or at least there are very few. Anything that focuses on a perfect world is a problem: whether that be a perfect past that conservatives fantasize existed or a perfect future that progressives believe they can create for us. Don't get me wrong: we can and should strive for improvements in our world, but -- and this is the crucial point -- not at the expense of the human reality around us. And that, to me, sounds a lot like the middle too.