The fact of the writing itself frequently unsettles people even if they haven't read it. Even when the reader agrees with the underlying statement, he may feel it was better left unsaid. Since daily life involves a substantial web of consensual deceptions, clear, logical writing may expose commonly held falsehoods in an inconvenient way. Whether or not he understands the reference is to him, you have won. When an essay of mine is distributed on the Internet and I get sincere but very upset email from someone who spent a lot of time thinking about it, I feel I have done well.
Writing is also an act of defiance of the Second Law of Thermodynamics.
Action Writing is a form of action. If you hold a beautiful idea up in public, people will attach themselves to it. If your idea is powerful enough, keep holding it up, for years and years. Good ideas tend to win in the end. Writing is also the evasion of action.