I was discussing this just a couple of days ago. Greens have terrible marketing and are in desperate need of a rebrand. I'm curious though: Which of their policies are you opposed to? Because honestly: if breaking up bank cartels, restoring Internet privacy laws, promoting local manufacturing, science and research as well as improving the calibre of education are bad, then I guess I'm bad.
For me, my criticism of Greens comes mainly from putting stuff in policies that would be better suited to "dreams and aspirations". They have a tendency to put stuff in there that are unspecific or at least out of the realms of what government does. But for all of that, I struggle to point to anything on their policy stuff and say "that's an awful position". At least, even if I'm not totally on-board, I see where they're coming from. And that's another point. Their policies page overwhelms you with too much to actually go through in one sitting. But, look at the Liberal/Labor equivalent pages? Greens are super open about what they stand for and what they would like to achieve. Labor have a few bullet points and Libs have a marketing brochure.