FWIW, I was not arguing against the use of RO/DI water, but pointing out that there is a difference between straight well water and municipality water in many places around the country.
I actually agree that it is probably not worth the risk to use tap water, since it takes the control of the water content out of your hands.
My tap water for example has 10 ppm of Nitrates in it, which would put me behind the eight ball as soon as I added the water. Not to mention, the obvious fluctuation that will occur throughout the year.
I think it is important to know the real picture as it relates to your own individual locations, rather than make sweeping generalizations.
In short, we all decide the methods that work best for us, and deal with the natural consequences of those decisions as they come.