Truth be told, when I'm talking to someone I haven't yet converted to the "button up" terminology (read: everyone), I say Oxfords, too.
Although, apparently, that's sometimes a bit of a misnomer, as technically "Oxford" refers to a particular type of cloth, and not all shirts I'd call Oxfords are made with Oxford cloth...
Most women's "man-tailored" shirts (good call, bemocked) do not have the button down option, for precisely the reason below. Many "man-tailored" garments for women do have various, now vestigial components that did have an original purpose, but have since become design elements soley indicating a sense of masculinity. Lapels on women's jackets, for instance, are no longer intended to be buttoned across the chest in case of inclement weather. Welt pockets are decorative rather than functional, etc. etc. So no purpose other than style, no.
Re: Button UPs
Although, apparently, that's sometimes a bit of a misnomer, as technically "Oxford" refers to a particular type of cloth, and not all shirts I'd call Oxfords are made with Oxford cloth...
Re: dusting off the degree...
Heheheh, it's so good to revisit my thesis.