A skirt is way more comfortable than shorts for hiking.
I pretty much always hike in skirt nowdays, at least in warmer weather.
The thing is this. Historically skirts were considered very feminine and not something an outdoorsy hiking type of woman would wear. i.e if you wear skirts and dresses you are not the type of woman who would wander off into the wilderness let alone be able to take care of herself. I even experienced a few years back when we would go away hiking on weekends. We would hike hard in the day and return to our simple hotel to wash up, change and wander down the village for a meal and some liquid refreshment in the pub. My friends would often be amazed that the dusty grimey woman from the day would re-emerge in the evening wearing a nice dress. They couldn't sync the two personalities in their minds!
Of course all this was few years back and mostly hiking in the UK or Ireland where it was not always warm or dry. Pants were probably the most practical in these situations. Also I was not really inclined to ruin one of my nicer skirts snagging on brush and rocks even if it was mid summer and hot. On the other hand I've never liked shorts very much and always prefered a skirt around town. On the trail if it was too hot for long pants I found shorts always binding and pulling and always longed for the comfort of skirt.
More recently though there has been a trend towards shorter length skirts in general and cargo skirts, travel skirts have come onto the market. This coincided with me doing more hiking in hotter Mediteranean environments or in the American southwest (amongst others). I quickly found that a skirt which fell just above the knee was ideal for hiking in. Usually these are inexpensive and nothing fancy. Tangling with thorney bushes and vegetation is rarely an issue due to the shorter length and if it is it's easy to just hold the skirt in for a few seconds. For me a shorter skirt is way more comfortable without a doubt and I look better in them. I suppose the only downside would be in cooler weather when you'd be unlikely to wear even shorts. I do still find though that occasionaly an attitude remains that becaause I'm wearing a skirt (even a specific hiking/travel one) I'm not a serious hiker and just a woman who's strayed from the beach onto the trail. Very annoying!
So as far as I'm concerned a skirt wins any way you look at it. I rarely hike in pants any more!