I suspect that Fr. Petras is a good man in search of the Truth. Some of these posts are devoid of courtesy and at times one smells the fumes of a Nascar race track in their coarseness.
It is a confusing subject. I think that a good argument may be made for the change in the creed. It sounds better without "for us men". "For us" is not so bad. It makes sense.
However, the words "man" and "mankind" are completely different. Think of it in terms spelled out by Ludwig Wittgenstein, a 20th century philosopher.
Words do not have one meaning. They have neighborhoods of meanings. Those neighborhoods are the environments in which they are used. "Man" and "mankind" in the neighborhood of Shakespeare or the liturgy has always been thought to have the meaning of general humanity. In a political convention or a labor union meeting they take on a different exclusionary shade.
In addition, I think it a mistake to view the liturgy as a form of social engineering in which political problems are corrected.
I could be wrong. The real point is our salvation.