I really enjoyed this eloquent analysis, thanks ! I did some work on the NeXT machine back in the day; it was interesting, but short-lived. For me, I see no difference, except outer format, between the Designer.cs code-behind in Windows Forms, and XAML in WPF, except that in WPF I found the XAML got in the way of designing, and designing got in the way of XAML ... but, perhaps I didn't hang in there long enough with WPF to reach even the first plateau in the learning curve (which most programmers do describe as "steep"). One reason for not sticking with WPF had to with my perception it did not have a reliable future, as an investment of my time, and intellect. Never understood why the code-behind in Win Forms wasn't written in some XML compatible format, anyhow.
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet