Funny you mention this...I've mostly gone away from trousers and toward skirts/dresses since I started regularly bike commuting ~11 years ago.

Short dresses/skirts eliminate the issues commonly found with trousers (getting stuck in chains, problems with the waistband while in the drops, etc.) Creative garments underneath make them appropriate for multiple seasons: unpadded "bike" shorts for warm weather, short tri-style chamois shorts for longer journeys, and leggings, etc. for extreme temperatures. Rain paints over the top, and we're good to go for the rainy season.

Granted, I will not be riding the weekly World Championships in a dress. They do bring with them some significant aerodynamic disadvantages.