Incidentally, I am still of the view I expressed here two years ago:
I support obeying the rubric, because it is the rubric and has the force of law. There is no very good theological reason, however, to admit laymen but not laywomen to the ceremony. The ordained versus the non-ordained or bishops versus non-bishops, yes; but if you are going to have laypeople at all, trying to restrict it to twelve men veers off into historical-reenactment territory. Now, historical reenactment is fine, and in fact it can help drive home some of the lessons of the Gospel, but let's not pretend that it is a theological imperative.
. . .
The sentence does say "men" (viri). However, people should be able to distinguish (1) given the way the rubrics are currently written, should a priest wash the feet of men only, or men and women?, from (2) is the rubric a good idea? should it be written differently?
My own view on (1) is, men only; the rubric is perfectly clear. As to (2), I see no theological reason to go either way, so you're left with pragmatic concerns. On one hand, restricting it to men helps duplicate the circumstances of the original event, which has a sort of teaching effect; it reminds us that the Church recognizes the distinction between men and women; and it emphasizes that the Church is willing to be "politically incorrect" about the liturgy and does not always bow to modern conceptions of everything. On the other hand, as mentioned above, it shifts the emphasis from the priest's act of service to the "worthiness" of those people chosen to be served; it's bad publicity and makes us look sexist for the sake of something with no theological significance; and it may cause women to feel that the Church does not esteem them as being as worthy to be served as men.