Well, I agree in the sense that this sort of crap is rarely relevant to a candidate's ability to do the job.
On the other hand, I do see a difference between the entirely fictional nonsense that obsessive conservatives have been throwing at President Obama since day one, and questioning Mitt Romney about some well-documented practices in the church where he serves as a senior leader.
I don't really believe that Mr. Romney supports polygamy, as I believe that the practice has been officially renounced by the LDS. He may have multiple houses and multiple positions on the same issue, but not multiple wives.
However, the baptizing of non-Mormons into the Church is another matter. His own father-in-law, a scientist who was fervently anti-religious, was himself "baptized" into the Church of LDS following his death. Aside from being monumentally disrespectful to the departed, that is just plain creepy.