I have a suspicion that Canon focused more on sharpness, with a view that other forms of distortion can more easily be addressed in software/silicon. I suspect however that this is becoming a more general trend in lens design, to primarily address sharpness, and to concentrate less on correcting spherical and chromatic aberration optically, and rather to finish correcting these in silicon or in software (albeit at the cost of some sharpness). This probably ties together with more of the recent cameras doing lens correction in their in-camera JPG conversion.
I think this is the case too. Spherical aberration typically has something to do with bokeh in a way that designing for the maximum MTF makes bokeh more nervous. Leaving some residual spherical aberration tends to improve the bokeh, and I suspect this has indeed been the case with the older 24-70. Increased sharpness requirements might aim for the future sensors too, too bad it tends to make bokeh worse.
Maybe people have been asking for more sharpness from 24-70, so that's what they get. Distortion and bokeh are the trade-offs then. What I don't know is whether they realized that bokeh will become worse for that. Also, for me it starts to sound that the new lens isn't as versatile as the old one, new one seems to be aimed more for people working at wide angles, while I think the older one was better overall at 35-70 mm range (the one I tend to use more). Basically, that's the reason why I have been asking whether those who own the lens have noticed a shift in their photographing habits. Call it being curious, then

I doubt it, I do not know how the many different lens formulas they have tried affect the variables. They try to balance all the factors, while, of course, giving maximum sharpness. One formula may be sharp but have curvature of field, another might have more CA, and some might have more lens elements running up the cost, weight, and reducing light transmission.
How do we deduce which lens formulas they tried and what their properties were?
I would not use the MK I, I had five and did not like any, and sold them. So any sustained use of the MK II at all would be different use.
Trust me, I'm very aware of the lens design process and the trade-offs and compromises included in that. But why would the actual lens structure be of importance to this discussion? Why would the designs that weren't selected as final candidates be relevant to this discussion? We know the 24-70 mk I and mk II specifications. That's enough for me to see the differences what they choose for the actual photographing (and which I listed on the first post), which is what matters here.
So far I have actually liked Canon optical design choices (I'd actually like to buy a few for the optical guys at Canon, but chances are I'll never meet them), but the new 24-70 makes me question about the direction they are going to go next. So, from what I have seen, the people who mainly photograph landscapes do like the new 24-70. How about the event photographers?