Considering the camera was designed to reflect the guild of much loved SLRs of the 1980s etc (FM2, FE2, FA, F3 etc), then where was the split K-type focusing screen? At least it could have been sold as an accessory. The 3rd party option was/is not cheap and was a mission to get. I also found the front control dial weird. At the price most punters expected more modern features for their money, notably the AF engine. There are other conspicuous features missing/wrong on the Df, which is why I sold mine to fund a Z7.
There is a lot Nikon got right in the Df, however. My Df served me well, including for wildlife photography in poorer light. Since 2014 (in my case circa 2016) a Used Df is still the most cost effective means to shoot with a D4 sensor, which has seriously underrated IQ IME. And the AF worked in most scenes but became increasingly shown up by newer DSLRs. However, this goes to show how almost all modern cameras work well in most situations, especially with experience going back well into the film era. With recent introductory discount, I invested in a D780 primarily for its Z6 sensor, which is excellent for lowlight up to ISO 12800, and also works well in silent-shooting.
As many agree, the camera has its fans but here again with a promising product, it's clear Nikon did not listen let alone respond timeously with a refined upgrade of the Df. This interview suggests Mr Goto believed he knew best, unfortunately
https://nikonrumors.com/2017/09/15/new-interview-with-tetsuro-goto-from-nikon-full-frame-is-the-trend-if-nikon-will-go-mirrorless-it-must-be-full-frame.aspx/If you have access to Nikon Owners Magazine (No 66, 2019) they published a long interview with Goto-San [
PDF attached], around his retirement in June 2019. Goto confirmed the Nikon Df stands as his personal project "My favourite camera is the Nikon Df. My thoughts were what sort of camera would I want to buy and own for myself? So I designed, planned and persuaded many of our staff members to [create] the Df. That is why I like the Df so much; it is my favourite!"