Why are people so interested in defining themselves along sexual identity and orientation in relatively recent western culture?
Why now? Why is it so different from most of human existence?
Because we are no longer facing famine. The Green Revolution has made our relationship with food so secure we no longer define ourselves in relation to it.
Throughout most of history people are farmers or ranchers or shepherds or bakers or butchers or millers.
So, we climb the Biological hierarchy of needs looking for our next characteristic that needs fulfillment.