Mark
I give up. I have tried to follow your logic and can only see that you have a strong POV about the need for multiple systems. I am making no effort to change anything you have said and frankly my point of view is based on my experience. Yours of course may differ . You have taken exception to most of the points I have made which is your right. I concede .
To clarify the point on Salgado s book. He chose to shoot three systems ,all film , for his book on Africa. The M6,R6 and the Pentax 67. I believe he used tri x for all systems so the look was close . The M6 and R6 images are essentially interchangeable . The 120 files of course look considerably different . One of the criticisms of the book were the differences ....how the 35mm looked when placed next to the 120 images in the book. It hurt the flow . I have had two different PJ tell me this is a consideration when putting together a web collection , a book or an print exhibit. Obviously this is a preference item and others may feel its a silly constraint . What I perceive as "apples and oranges " may be "peaches and cream" to others.
That's the point. It differs person to person.
BTW, I don't confuse need with want. I don't need anything except a D3 and a couple of zooms to do 90% of my work.
However, I want more.
Just like people adapt Leica lenses to Canon cameras ... or any number of custom things people do to get what they want.
Why should I limit myself to a "system" that comes up short in certain areas? Just get the another one that excells at that specific thing.
I'd immediately settle down to a single system when and if one can do everything I want to do.
It's a fairly common lament that Nikon is weak in fast primes, Canon isn't ... but is weak in wide zooms. Sony has some fast primes and excellent zooms but lacks in other areas. So, should I limit what I want to do because the one system can't support it?
I've never had a problem with choosing glass first and the system second.
It's Peaches and Cream to me.
