The agenda of the Left is to deconstruct marriage and gender until it is meaningless. The social norms we saw as historical stable development in society will be deconstructed so no moral judgment is acceptable.
It ultimately feeds the undeveloped primitive nature of society and the baser nature of man taking us back to the laws of the Jungle. Social structures to them are a hindrance to "do as you feel".

The agenda is to destroy the social institutions that teach the structures of society.