My original comment was that it doesn't make much sense to downplay technological improvements out of brand loyalty. Whether the improvement is great or small has nothing to do with my original point.
If you are attempting to have a logical debate, it helps to properly sequence your statements.
No, your original
point in response to my offhanded remark was an analogy comparing the improvements in DR and resolution of the D800 to the development of camera autofocus systems and digital image sensors. In other words, you compared modest, incremental improvements to transformative changes in technology. That is a completely fallacious analogy.
Now, if you're referring to your second
point, about downplaying technological improvements due to brand loyalty, I'll ask you to refrain from ascribing motives to my statements, that's presumptuous. I'm downplaying them because they're modest, incremental improvements. Are they beneficial? In some situations, certainly. Do they benefit the vast majority of photographers and the vast majority of shots they take, as is the case for AF and digital sensors? No.
Frankly, most of what we see in the newest dSLRs today are modest, incremental improvements. The 1DX has the fastest frame rate of any full frame camera, but 12 fps is still only a modest, incremental improvement over the 9 fps of the D3s. The improved low light AF sensitivity of the 6D (-3 EV) is a modest, incremental improvement over its predecessors (and adds sensitivity in a range where either ISO is so high as to limit utility of the shot, or shutter speed is so long that you would have time to focus using live view with exposure simulation anyway).
Now, if you aggregate the incremental improvements across multiple updates, you often have what amount to significant improvements. Of course, that only applies within a given line – I'm still struggling to figure out what the improvements are, if any, between the new T5 and the soon to be four updates-old T2i. I do think dual pixel AF is a significant advance, though.