Completely correct both of you, but is it really so that this is a big problem now? Don't we already have affordable glass that deliver the amazing image quality and we can with a quick raw conversion tinker what we need in PP,,,
For the 50mm f/1.8 S, it does have notably higher MTF than the current F mount AF-S version. There are high quality 50mm's such as the Otus and the Sigma but they are huge and heavy. I think the new 50mm f/1.8 seems to strike a good balance between weight and image quality. If the vignetting is also low then it could also be used for indoor available light images with an advantage over current f/1.8 lenses. The 58/1.4 AF-S has low vignetting but particularly soft corners. With the new mount I would expect such compromises could be avoided. Also on the Canon side their new 50/1.2 R seems to be significantly sharper than their EF mount version. I am not saying that this is all about the new mount, could be simply that they are made to a higher standard, but they haven't done that with the DSLR 50mm lenses that they produce.
The situation is that we all have tons of legacy glass,,,
Quite right, I am quite happy with my existing Nikon (and third party) lenses for the F mount but a couple of exceptions only.
Other mounts have emerged and died out quite quickly,,, I fear the Z could face the same unless the lenses really are spectacular and relatively affordable.
I think the first three lenses seem quite competitively priced given the image quality (though obviously the image quality needs to be assessed in practical use). The Noct is another situation but if Nikon bring out both a 50/1.8 and 50/1.2, then most people won't need to consider the Noct.
If they are as I fear, with various defects lateral chromatic fringing as some already report and f/1.8 I'm just raising my concern for selling off my F's and replace then with inferior Z's,,,
Lateral CA can be corrected in software and thus it can be seen as an easier-to-forgive error than, e.g., longitudinal CA (which can also be corrected in some way but at least the algorithms that I've tried have been very slow).
I doubt the new Z lenses will be inferior. It's just as the sharpness increases, it is easier to see CA if uncorrected (since other aberrations are so well corrected). I also don't think it has been Nikon's aim to make apocromatic lenses; what they seem to go for is a "pleasing overall look", though there are exceptions. The trend is now towards the greatest sharpness and somehow Sigma got ahead of Nikon in this when the 36MP cameras came out Nikon seemed to be a bit unprepared, and only more recently have been putting out lenses that take greater advantage of the high-resolution models.
Although I think Nikon lenses yield beautiful results I think they really need to work on the perceived value in the eyes of a typical customer aspect.
The pro sport shooters, birders etc. will not like sluggish or unpredictable AF so it seems we will have a very long grace period or transition to Z, if too slow it will die out,,, Sure they keep the DSLR and F-mount - Rally vice decision as a fall back! IMHO
I think it's not necessary for the system to be the best for sports or bird in flight photography; it can exist as a portrait, wedding, event, travel, landscape, video system parallel to the DSLRs. I think only a small percentage of photographers get into telephoto action due to the costs involved (not to mention heavy gear as well) and a system doesn't need to be the best at everything to find customers.
I don't think the Z system will fail. If it does, then Nikon may fail as well, since the constant drummaging by websites that make money from switchers and buyers of the latest gear has imposed on people's minds that "mirrorless is the future" (and the only future). I personally find that it is great that there is a diversity of different technologies available and prefer the DSLR for my use but sometimes this kind of waves of consumer buying trends take over and investors can make decisions that affect us in adverse ways. Also there are so many posters online who cannot tolerate diversity and want to impose the same type of camera on everyone. This is something I really dislike. Let people decide for themselves.
One advantage that the large diameter mount may be more stable when used with adapter and existing F mount lenses. The larger diameter means the forces on the mount (from a lens that is acted upon by gravity to twist the camera mount) should be a bit smaller.