The primary reason for using IP and higher generation sources is to get the cleanest transfer possible to begin with, and the one closest possible to the o-neg. I agree with you that the theatrical should be kept in mind always, and to be perfectly honest If I had my way there would also be a comparison scan of a well-kept theatrical print for extreme reference, as to fully match the original color timing and presentation as possible.

The color timing is what is typically lost in transfers, and without the theatrical in mind there's no chance of fully replicating it. The best example of doing it correctly I can think of is the Criterion Spartacus, for which Robert Harris and the colorist used specific multi-frame references from the 1991 restoration to hand color the DVD master in order to properly preserve the film. Universal scrapped all this for their Blu-ray in addition to heavy image manipulation.

With a pristine release print, it is possible to make a great master and release. What you have to deal with is a greater chance of deterioration, generational loss, improper printing or anything else that could have arisen in the printing process. Additionally you are stuck with the print audio instead of higher generation materials, such as the audio masters.