Thank you all for the explanations!
So typical of me, I never considered the look of my legs or anything as a reason for wearing / not wearing shorts. (That's right, haven't got an once of consideration for others and if I might be blinding them, hehe.)
I also feel more exposed in shorts than a skirt. Shorts seem more revealing to me, because they show your shape. I mean, like, isn't that weird?
And I don't feel constricted in skirts. Then again, I was raised Edwardian and to walk, for example, without swinging my arms. I.e., constriction is a way of life, ahaha!
Knee pants I'd be more inclined to wear... as part of a suit, to the office. Right. I know. That's even weirder.
I don't know how different I'd be if were a gym-goer or capital A athletic. I mean, my bike - while not strictly a *girl's bike* - is skirt friendly. However, I'm pretty sure if I lived in So Cal, I'd probably at least own a pair of shorts. Maybe if the weather here in the Bay Area were warm (instead of being cold with a flash into the 90s-100s in Fall), it would be different yet again...