the inverse is true for print. i.e., Sans for header and Serif for body for print documents.
Now, re-read this: Microsoft did partly address that by making Cambria and Calibri its default header and body fonts (for Word)
Did they get it mixed up? I think so.
Personally, I think there is no point splitting hairs over whether they goofed up or whether it was intended... MS-Word as a product is intended for the "write it, and then print it" market (whether the actual printing happens or not is another thing altogether), and for that demographic, the typographic convention is Serif for body text and Sans (not a necessary condition, though) for heading [0]. And from that point of view, the design choice is mixed up. Right or Wrong, that was the only point I was trying to make.
[0] Again, I am aware that "is serif readable?" is a different can-of-worms altogether.
I.e., it's not the design choice that's wrong, but the assumptions about who Word is now intended for.
>> MS-Word as a product is intended for the "write it, and then print it" market (whether the actual printing happens or not is another thing altogether), and for that demographic, the typographic convention is Serif for body text
Same convention holds true for typesetting packages like Quark/InDesign/LaTeX, etc. The established convention for documents cranked out is what I mentioned earlier... So regardless of parent poster's/your opinions [0] on this topic, the choice is mixed up because body text ought to be Serif (and heading something else if needed).
[0] it's not the design choice that's wrong, but the assumptions about who Word is now intended for
And the evidence for this position is this design choice made by Microsoft. I'm treating it not as a mistake, but as part of proof that they've consciously chosen screen-viewing instead of printing as their goal, and applied that convention for their apps.
What evidence is there that the current MS Word is aimed at printing primarily, and because of that its "body text ought to be Serif" ? It has been aimed at printing a dozen years ago, sure, but why you're reasoning that it still is now?