Do you have any evidence to support the idea that communists are infiltrating the Greens?
I can see nothing wrong with supporting the right for same sex couples to marry, or in treating asylum seekers with compassion, and I was never under the impression that the only thing the Greens cared about was trees. Adam Bandt is the elected representative for his electorate, and perhaps in his victory speech, he was voicing the concerns of his electorate, after all, that is his job now.
Why shouldn't the Greens have a variety of policies? To become a voice in government they must have policies in a broad range of areas.