Well, everything I’ve seen indicates he did really write it.
That said, should we accept everything said in it?
Like everything else we need to think it through.
First he states that mens trousers cling to women more than skirts would (he acknowledges skirts and dresses can also cling but believes mens trousers do so more). I would argue #1 that mens trousers actually sag on women and often HIDE a great deal. I should know. For some 3-4 years I only wore mens clothes because they hid my body and I was ashamed of my body in my teen years. Womens trousers tend to hug the curves much more.
Second he states that women who wear pants are rejecting their femininity. In which culture? Certainly not in our current culture where womens trousers are a thing.
Third he states women who wear trousers are diminished in the eyes of their children. Having been raised with a mother who wore trousers I must be the exception because I didn’t experience this.
I think he was well intentioned but wrong on many points. I do think he was trying to address a deeper problem but got caught up on the incidentals.