And I think we are all likely to make exceptions for our favorite brands even while condemning others for making the same choices.
And I think you hit upon exactly the key issue here: defining what we mean by "fit."
And perhaps that is what I have struggled with as I reconcile my earlier conviction that the movement MUST fit the watch case with how I feel now, namely that "fit" may mean different things for different watches.
THE example that got me thinking about this issue, and one that has not yet been mentioned here, is the cal. 849 by JLC used in both the Master Ultra Thin and the MUT38. (An example not dissimilar to the Dufour Simplicity you mentioned.)
I think I have felt at odds about this move by one of my favorite manufacturers, to put a truly fine caliber that might be considered small even for the 34mm case of the MUT into an even larger case for the sake of creating a watch that would appeal to those who prefer a larger size. The cal 849 is really small, really thin and really robust -- it is a brilliant caliber in many, many respects. So, why not use it in a larger model? It is a simple time only caliber without even a seconds subdial to create issues on the dial. To my eye, the cal. 849 fits the 34mm MUT about as well as it does the 38mm MUT. And yet this really bothered me when JLC first released the 38mm MUT.
Now, not so much.
Was this a decision by a manufactuer to take a tried and true caliber once in a "classic watch" and place it in a ridiculously large case? No. On the contrary, the decision furthers the life a of a caliber that, perhaps, cannot be improved upon. On a personal level, I find that I cannot comfortably wear the 34mm MUT (and I have tried it many times, always in vain). But I can wear the 38mm version, which is also a bit thicker than the 34mm, but otherwise loses nothing in the translation. So, for me this is an interesting moment where it is is hard to define "fit," and yet I recognize that there is a good fit here. I think the problem I had originated with this enthusiast and not the manufacturer, as you suggested.
At any rate, I think it is clear from the names mentioned thus far in this thread, there is not a single one of the "top tier" watch manufacturers, including even the leading independents, that has not had to address this issue of "fit," in one way or another,and it would be impossible to honestly condemn one without condemning them all.
Again, I find that it is a good thing to question my biases -- it might, happily, help me to add another watch or two to my small collection.
Best,
respo