I totally agree. I have nothing against providing the best for the ladies, even as women-only events, as long as you make it available also for the guys in one way or another 
In this vein, I have contacted Zwift support, asking why the event was set up like that and suggesting that category D, currently unused, be used to host an open ride on the C route, therefore providing the same opportunities for all the riders, regardless of gender.
Zwift Support replied that they brought this suggestion to the dev team for their review, but that they cannot guarantee its implementation in this year’s event, as it’s up to dev team.
They also said that the more attention a topic gets on the forums, the more chances are for it to be acted upon.
One other thing that I asked them was to let me know how such an obvious “reverse gender inequality issue” can be officially escalated to Zwift management, to flag this approach as not consistent with the Zwift proclaimed values of fairness and equal treatment towards their user base… I haven’t received any reply to this 