Why do I do this? --
As time goes on I find myself drifting out of the "evaluation" phase of my disaffection with the LDS church and into the advocacy phase. Before we were kind of studying all this out together to try and figure it out. Now I have basically made my decision and am trying to point out things to help clarify other people's thinking.
To destroy the church or something similar? Not at all. I have no hope whatsoever of influencing the institutional LDS church. I might, however, help alleviate some of the cognitive dissonance people unconsciously feel as they experience the disconnect between doctrine and practice. I think being able to see it for what it is helps people process it in healthier ways.
Another point my wife made is that there are a lot of people trying to deconstruct the LDS church based on historical or cultural issues. There aren't many people out there deconstructing it from the inside based on doctrinal issues, because most people who get to this point just hang up their cleats and leave. So maybe it's useful to approach the LDS church from the truly believing perspective of someone who has actually studied the scriptures, believes them to be generally true, and wants the LDS church to be consistent with what should be its own teachings.