I
don't fully get your argument but I do sort of get your general drift but part of the problem is you aren't being specific enough or we're doing apples and oranges.
Yes, 36 and 42 = miniscule until you have to make the things and squeeze the right IQ out of it and then it's not so miniscule. It's like saying that the difference between a 3m59 sec mile and a 3m50sec mile is miniscule. From your armchair, maybe, but just remind me how much the other greater than 36mp sensor cameras cost?
Ditto your comments on focus and IS. I don't believe that any DSLR can match the focus accuracy and consistance of any of my csc's for the shooting I do but for people who need speed or ultimate tracking a few missed shots here and there and the odd week or two trying to MA lenses is a none issue... and show me a DSLR which will give every lens IS please
It's about choice.
Ref dropping users. Remind me how well Nikon are supporting their csc users and tell me how much effort they've put in to building a quality aps-c lens line up. And of course Canon has never dropped a mount