I have a few points to make here.
Firstly, organised religion is about social engineering. Thus, the topics covered tend to pertain to things like sex (reproduction) and marriage (the family unit).
Secondly, Christianity belongs to a category of religion called ascentionism, as opposed to descentionism. An ascentionist believes that the answers are found by ascending, or "rising above" the flesh, into the spirit world where god lives. A descentionist believes that god is IN the flesh, therefore godliness lies in the material world.
As for the elders using lurid confessions to get a stiffy, that you can bank on. It's a direct result of the sexual repression of the JW religion, and probably also tied in with what their wives won't do for them in bed. If you only got laid once in a while and only in the most "vanilla" way possible, wouldn't you want to hear what freaky stuff others have been up to? Especially if you could do so under the guise of "holiness"?
As for pornography, the whacktower is an excellent example of pornography, it's just not sexual.