my notion that Boeing is/was a more personal company than Airbus is finally exposed as groundless fantasy.

Really? Once WWII came and brought a huge expansion of the company’s size, I wouldn’t have expected Boeing to be a family shop…even if Boeing senior had several sons.
In contrast, UK aviation firms were usually smaller, concerns…and often family run. At least that’s the impression I get from reading my Putnam books and Hamilton-Patterson’s Empire of the Clouds.

I’m not saying one is better than the other, but as the industry developed (along with huge R&D, design and production costs), firms had to get bigger or merge to remain viable.

Douglas was very much a “personal” family organization…and not necessarily for the better.
Author Rene J. Francillon makes that very clear in his excellent book Douglas Propliners, Haynes, 2011.