Yes, it is all about power and control -- but porn is very much part of what the authorities do not want people to see.
Your sexuality is the most personal, most intimate part of your life. By enforcing "morality" - the state exerts control over your sexuality; it exerts control over the most intimate part of your life; for those in authority, it is the most potent symbol of their power possible - and the most intoxicating validation of their status.
Those in power are there because they are pathologically inclined to seek it. They cannot help but expand that power, to intrude and control others to the maximum extent possible.
Your sexuality is the most personal, most intimate part of your life. By enforcing "morality" - the state exerts control over your sexuality; it exerts control over the most intimate part of your life; for those in authority, it is the most potent symbol of their power possible - and the most intoxicating validation of their status.
Those in power are there because they are pathologically inclined to seek it. They cannot help but expand that power, to intrude and control others to the maximum extent possible.