We rarely choose ideologies for their logical and factual merits. Even when we do, the choice itself limits us to continuing that train of thought. We are bound up in something greater than the intellectual debate, being cast up and pushed forward by the waves of history. It still makes sense, but that sense is removed from pragmatic, skeptical thinking. For some political thinkers, ideology seems closer to religious rationale than to science.
Ideologies are anathema to reason.
Their inner logic usually fits snugly around underlying assumptions, but for the average follower, the logic is mostly superfluous. The debate is mostly over once you write it down. For a novel, whatever is left to discuss will be between you and your literary critics, and if you are good enough, between teachers and students in those rare schools were literature is debatable. For those of us with less education, if we actually read anything other than magazines, we at most would like some parts of the book and not like others. The scholarly debate would be incomprehensible, boring and even pretentious.