It's a good method of drawing people out. To find gaps in their stories. The same method can be used in discussions like these boards. Who better to argue with sometimes than yourself? We all do that in our own day to day live in deciding our actions.
Someone with a radical or semi-radical viewpoint will often times draw the fire of everyone on the board to defend, or try to change the viewpoint, OR point out where the radical is wrong. That allows non-responding reader to learn what other people have learn or think. We too often assume that everybody knows everything that we have learned. It's a good method to draw out old information for new readers on subjects like 'was Slavery the cause of the War'. It is also a good method to challenge peoples opinions where quoting a document source will not change their minds. To find out what they really are thinking.
And like you said I've been yanking your chain. You kind of fell off the boards for a while, which we all, who have been on these boards for years, do from time to time.