To each his (or her) own, of course. My tongue-in-cheek comment still stands that the 35/2 is the best 35, bar none, for the Contax G.
Having owned Contax G cameras since about 1995, I have a lot of experience with the cameras and lenses. The 35/2 has always been described as a 'lesser' lens than others in the line, but I have never honestly seen a side-by-side illustrating this claimed inferiority. Rather, the quotes I've seen are all tied back into the MTFs, and many of the people making the statements (not on this forum, but others) haven't ever used the lens. It may well be that the 35 is not quite the equal of the 45 (both being Planars) but this in no way means the 35 is 'bad.' It doesn't even mean that such differences are even easily visible...if the inferiority was that obvious to you, of course, that is all that matters.
The rest of the line sets a high standard, and if the 35 is under that standard, it certainly doesn't necessarily mean it is junk, and not even worth the bother of selling.
I agree 100% with your statement that 'people can vary as to what they think good IQ can be.' Especially when some of these people are just comparing charts...and not actual photographs.
I choose a lens based on whether I like what it produces, or not...not whether someone else likes it (or not.) I also find lens comparisons to be tedious, so I never bother doing them.
Certainly the vast majority of G shooters owned the 28 and 45, as the 35 wasn't introduced until later, so it is less common, and perhaps less desired due to the closeness of the focal lengths, as you explain.
On the Nex, the 28/2.8 becomes an equivalent 42/2.8, which isn't of much use to me compared to a 50/2 equivalent. The 45/2 on the NEX becomes too long...again, for me. So, for me (and Cindy and Terry and a few others I know) the 35/2 is the Contax G lens of choice.