This is of course just an opion, isn't it?
No, there are many objective facts which make it so.
Facts not having to do with the sensor, but the functionality.
Did he inform you what his personals reason were? Would those be something which prove without a shread of doubt that your opinion above represents the objective truth?
Here you go, Abe, right out of Scott's own mouth, on a public video, he personally displayed on his own website.
Why I Switched to Canon, by Scott KelbyIs that "evidence enough" for you?

1Dx worse low and middle ISO, similar high ISO, significantly inferior colour separation, thus for colour image you can expect slight drop in SNR as well as colour accuracy.
This is according to DxOMark measurements.
The disparity is not that great in either color depth or ISO.
It is the other features (e.g., get your head out of "the sensor" only) that make the 1Dx a more versatile tool.
What erogomic studies you have been made which have resulted in that observation? What kind of far better functionality it has? Or is it because it's a Canon, thus it must have better usability/comfort? Can you offer any evidence towards you "far better ergonomics/functionality" statement?
Ergonomics are a subjective evaluation. The "evidence" I have would be 3-fold:
1) When I personally went shopping for cameras, at the time it was between a Nikon D300 and a Canon 7D. I chose the Canon because it fit better in my hand, did not have a "ridge" on my fingertips like the Nikon, but a smooth indentation instead. I simply liked the way it felt better;
2) The video I just provided of Scott Kelby, a professional who likely earns more from his photography-based profession than you, saying essentially the same thing: ergonomics and overall functionality are superior (IFF you actually watch the video);
3) The fact that more sports photogs shoot the 1Dx than the D4.
It's just a sensor which is just 39% of the size of the full frame sensors and that is the key metric -7DII has nowhere near the same image quality potential either of those full framers have.
I agree. It is just a sensor. And therefore only
part of the overall equation as to the value of a camera in the field.
No one can realistically expect the $1800 7DII to offer better overall resolution than the $6000 Nikon/Canon high-end sports/wildlife cameras.
But it
does offer some (non-sensor) specs that are
better than these cameras, with image quality that is good enough to get published in any magazine you want to talk about.
Anyway, sorry if I ruffled any feathers

Have a good one,