I agree that there are many bands who have "key" members who don't appreciate the whole "sum-of-the-parts" concept, but what makes you think Hynde doesn't appreciate Farndon's input (or did you mean at the time)?
I read her auto biography, where she stated that Farndon was very definitely not a "muso." The context made it seem that she was somewhat dismissive of Farndon as a bass player. She also fired Martin Chambers for periods of time, as she did not feel his drumming was up to snuff, at least in comparison with some other drummers that were available. She did seem to appreciate the musicianship of Honeyman-Scott, but did not appear to think that the other two were all that great. I think that both of those guys, Farndon and Chambers, were grossly underrated- as perhaps was Honeyman-Scott. Without Honeyman-Scott, I don't think there would have been a Johnny Marr. The influence is pretty obvious. In other words, I think the whole band was great as a band, and while Tony Butler may have been a superior bass player in certain contexts- I don't think he sounded as good with that band as Farndon did. I don't think Ms. Hynde appreciated that. Hey, I could be way wrong.