If I were to argue anything(which, BTW, I'm not arguing at all here) .. I would always argue in favour of an electronic display as ultimately being the best option for the future.
I think you've mistaken my replies as arguments!
You asked the question .. why? .. (this or that) and I'm simply adding possible answers.
Why don't Nikon or Canon develop a mirrorless camera .. well they both have as far as I know.
Why don't they wholesale replace SLR designs with mirrorless types .. I think the answer is obvious(from what we can ascertain) .. that it'll add to the cost of development relative to what they currently offer.
I gave the lowest end of the market as examples simply because the theory of an EVF system being lower has yet to transpire!
But even at the top end of the market, it's easy to assume that the reason they don't switch design types is most likely due to emerging tech .. I did post a link to Canon's latest patent design.
My personal preference is for a true hybrid design as OVF will still have an advantage over an electronic display(eg. in terms of ultimate dynamic range to the eye).
For landscapes, this is my preference.
Battery life! .. EVF's use up far too much power for all day use .. etc.
You've just listed the major issue with an electronic device outputting to another electronic device.
If too many pixels become defective both on the sensor and the display .. the camera would be horrid to look through when trying to compose your photograph.
If the defective pixel locations coincide on both electronic devices, you additive viewing issues.
Dead pixels on a sensor can be dealt with easily for the final image in PP .. that's been a redundant issue from about day one.
You can't really deal with defective pixels in a live view/real time situation .. and mapping those dead pixels does nothing for the viewing experience in some situations.
Dead pixels on your sensor is not the same thing as dead pixels on your monitor.
Imagine a clump of dead pixels on your PC monitor .. would you just put up with them? Most folks purchase brand name monitors because there is usually a defective pixel assurance.
You can't fix them in any way .. the only solution is to replace the monitor.
Mirror surface technology is pretty mature to the point that you can safely say that (clumsy cleaning practises aside) .. they are pretty durable and I dare say manufacturing processes would produce high yield rates. And while I don't know this, I'm sure I'm safe in claiming that the yield rate would be far higher than for very high res LCD/OLED production.
And I'm sure that yield rates are what is the issue would be for the current reality of price comparisons between the low end of the camera market.
In an ideal world where all production processes yield 100% success rates .. for sure his res displays in camera would make them much cheaper.
It's the same for the sensor market. The larger sensors additional cost is not due just to the larger size of the silicon .. it's the yield rate of that sensor + the reduced number of devices for each silicon wafer that makes larger sensors more costly. The yield rate is a significant component to the equation.
I think that the introduction of Live View is possibly just enough EVF for some DSLR users fro those times when they need the advantage of a digital display.
And I have to stress here, I am a massive fan of the potential of an EVF system over a OVF system!!!
But, as far as I've seen, the disadvantages of the EVF are still too great to completely remove the OVF from the equation of a camera .. DSLR or otherwise.
For those times as you said like macro when absolutely perfect focus is needed, or the lens aperture is just way too small for any light to pass through to the OVF .. Lv mode is plenty as a form of compensation.
So my thoughts are that CaNikon probably see things in a similar way to my thoughts for now .. so they probably have the belief that there is no need to change anything .. YET!
if they simply follow the current manufacturers(of MIL cameras) it makes it harder for them to then take the lead in any significant way.
They can introduce a higher res EVF on any give model, but then so can the other manufacturer in their next model iteration.
If they perfect a better way(eg. this hybrid system Canon has recently released in patent form) it gives them a significant advantage down the track.
So the advantage (from CaNikon's point of view) would be that whatever Sony/Olympus/Panasonic/Fuji can give you, so can they. But what those other MIL only cameras can't give you .. CaNikon can!
I don't think that mirrorless cameras are the answer .. or
only answer.