First, a lot of people who attend don't know who's organizing and when they do, don't come back.
Second, prior to FR DC countering them, nobody countered them on a regular basis. Prior to that, it was Mardi Gras time for the marchers. The reinforced each other's beliefs because the only heard each other's beliefs. Since they are people with low esteem and subject to group think, that anyone else has a different opinion drives them away. They don't want to be in a conflict, they prefered that sinle opinion cocoon.
Well put!