I was often given the extremely laborious task of hunting down volunteers for the Mandatum. It was hard work: in my experience the majority of men who attended the Maundy Thursday Mass just wanted to pray quietly, and being asked to get up in front of the entire congregation and take off a shoe was anathema. I soon discovered that married men and those accompanied by their mothers made the easiest targets; the women were often eager for their menfolk to participate, and would help to persuade their reluctant spouses and sons to do their duty.
Given this reluctance, I suspect that we shall see an interesting phenomenon. Rather as the proportion of boys serving at Mass decreased as girls were permitted, I predict that, in parishes where the new rubrics are observed, we shall see the gradual (or not so gradual) dominance of female volunteers. After all, we have (on the whole) prettier, more dainty feet than men... and generally less foot odour. I foresee reports in L'Osservatore Romano commenting on the latest fashion in shades of nail varnish... The proportion of women to men can be called the Footsie Index...
I never felt excluded because I couldn't have my feet washed on Maundy Thursday. The link with Jesus, the Apostles and the life of service and self-sacrifice to which priests are called seemed perfectly clear. Opening the Mandatum to women merely breaks that symbolism, and so impoverishes and cheapens the action, reducing it to a play-acting stunt.