Why Not?
Because truth isn't always something as clear and unquestionable as we may desire. In many cases, such as in topics related to social sciences, there is no "truth" but simply opinions and assumptions. Which is the best political system? Was this or that government a good or bad one? There are no "true" answers to such questions. There are facts, opinions, facts about opinions and opinions about opinions.
Besides, truth is only a boolean value (only 100% true or 100% false) in certain technical contexts, such as maths or programming language. In most other topics, there is more than truths and lies under the sun: there are half-truths, lack of context, words with double or unclear meaning, logical fallacies, cherry-picked pieces of information to lead the reader to a predetermined conclusion, inadvertent reuse of someone else's lies, even misunderstandings. A statement may fail to adequately convey the state of affairs regarding some topic, without that statement being an actual lie.
In other cases, accuracy itself is under dispute: a certain question may indeed have a "true" answer, but lack of complete information leads to people supporting a variety of possible answers. For example, the existence or not of extraterrestrial civilizations, or the nature of a certain unidentified flying object. There is indeed a factual answer (either there are extraterrestrial civilizations, or there are not), but we are not 100% certain of it.
Read more about this topic: Verifiability, Not Truth
Famous quotes related to why not?:
“When I consider the short duration of my life, swallowed up in the eternity before and after, the little space which I fill and even can see, engulfed in the infinite immensity of spaces of which I am ignorant and which know me not, I am frightened and am astonished at being here rather than there. For there is no reason why here rather than there, why now rather than then.”
—Blaise Pascal (1623–1662)