For some reason I am chief clothes ironer in this house and it annoys me how much harder my wife's things are to iron than my own. This is despite the fact that my clothes tend to be much bigger and have a lot more material to cover.
Reason 1: My clothes are all made out of cotton that can be steam ironed at high temperature. My wife's clothes are made out of a variety of light materials that will melt at anything above luke warm.
Reason 2: Male clothing tends to be made up of a number of large flat panels. You just lay each panel flat and iron it. Even sleeves and trouser legs can be laid flat. Women's clothing tends not to have flat panels. It is made up of irregularly shaped pieces of material which are sewn together in escheresque arrangements. It is literally impossible to lie them flat.
Reason 3 accoutrements. My clothes are all fairly basic. The only accoutrements you need to watch our for are the occasional button. My wife's clothes almost always have some kind of flounce or flourish which either needs ironing in its own right or needs to be carefully avoided while doing the rest of the garment. These accoutrements can more than double the time it takes to iron a garment.