Well, wearing of trouser should never be a crime; it depend on the contest or where the lady wears the trouser. Take for instance, if a wife wears not even a trouser; let's say a short before her husband in the house, I think its never bad and same applies to a young Lady in the house or room where men can't see it. But, I can vividly understand the reason why the two most popular Religions kicked against it totally that " men should never wear those dress made for women and vice versa."
The abuse of females wearing the trouser is totally inevitable; imagine ladies of this days don't even wear the trouser anymore, they have graduated to putting on what they call "bomshort". With almost all the iimportant parts exposed. Some will even wear leggings; that will bring out all the curves and shape of their private parts. It all what the ladies tagged as civilization; buy in a real sence. Its all evil and must never be encouraged.