The members of SDS were unhappy with American society because they felt that it had abandoned idealism and had allowed itself to become complacent and happy with material wealth.
The SDS wanted a society that would actively try to seek utopia. It felt that human relations should be based on love and human brotherhood. It felt that contemporary American society was not based on this. Instead, it was based on people trying to exploit one another and people only relating to one another on the basis of group membership. In other words, the US was a society where whites oppressed blacks and employers oppressed workers based solely on their group memberships. They did not see one another as people and deal with one another on that basis.
The SDS, then, had a utopian vision of society. It wanted people to feel more personally connected to one another. It wanted them to feel more empowered so that they could take over society, make it more democratic, and thereby create a utopia.