I think the reluctance of some to switch to nuts had to do with concern over whether enough solid pacements could be found for them in areas like the Gunks. A nice chromoly angle in a sound crack was a very solid anchor. You didn't hear people talk about building equalized anchors. We just knocked that pin in and clipped to it. As the transition to nuts was occuring, I recall hearing folks saying that nuts were fine in areas with lots of vertical cracks, but that in areas like the Gunks where the cracks are predominantly horizontal pitons were best.
John Stannard mentioned in his Eastern Trade publication at the time that clipping a good pin was "...just like stepping off the ground..." in terms of protection and that with nuts, you needed to be much more careful and knowledgeable about the placements. He also asserted that you needed to place about 30% more pieces, owing to the passive nature and smaller contact area, in order to achieve the same level of protection.
To show what was possible, John published a list of "First Clean Ascents" in one issue of the ET. Seeing routes like Squiggles Direct, MF, and Arrow on that list were eye opening. (Remember, this was years before SLCDs and tri-cams. Many were even done pre Chouinard hexcentrics.)
He also advocated leaving any pins in-place, since the bulk of piton damage to the rock occurs during the removal process. John collected pin donations from climbers who made the transition to nuts and if you left a pin on a climb, he'd give you a "free and cheerful replacement." Thus, many of the popular trade routes had a fair number of resident pins on them. At one time you could do Jackie and Classic with just a rack of draws. That coupled with rap placed pro on Arrow, Pas de Deux, et al actually put the Gunks at the forefront of sport climbing years before the term was coined.