I am 80 and now see what an advantage Guys had over women. In the 50s people from the North called groups of people YOU. Then later they began to say you Guys because it was usually guys, like in the Harvard Library or Presidents. I was the only female running track with the boys and also the only female in the premed club at Baylor for 4 years. A professor from the NORTH said "good job you GUYS" and I was pretty thrilled to be Called a GUY. In Full Metal Jacket the soldiers are called Ladies to make them mad enough to kill.
In Maids, it is all women in a group and they say Hey Guys. It has caught on so strongly in movies etc that now it is so common. Can people hear how this is such a reverse put down? How about calling big groups Hey Ladies?"