It doesn't answer why he made The Illusion of Truth, other then just because he was annoyed at something in the news and decided to use B5 as his personal ranting device. I'm not watching B5 to see JMS go on tangents about things he doesn't like at the expense of the story. It was the worst segment I've seen of anything on tV for a long time. Its supposed to be a good sci-Fi show, not JMS's personal soapbox.
Simple. By now it should be obvious that the underlying core of the show is that it's about process. The process of how a government goes bad. The process of how one person creates change. The process of redemption. These episodes you hate so much illustrate the process of how a government can get to the point of dictatorship and complete control over the people.