Trevor,
my other concern with your defence of Australian Marxism's understanding of historical materialism and materialist philosophy is that it made no real attempt to address the question concerning technology. You say that this materialist philosophy understood the way that the processes of capitalism destroyed the environment, and that Canberra's attempts to address this can only be a corporate solution. You write:

"The trouble with the politicians that are out there engaging in genuine issues that matter to people is that they almost never come up with anything but a corporate solution. One has to watch out that Heidegger doesn’t become a convenient ideological smokescreen for doing this kind of thing. A satisfactory solution to our environmental problems cannot be a corporate one."

Your materialist philosophy is silent about how we can counter this ethically through better practices. In fact it is quite hostile to ethics as it speaks in the name of hard realist science plus political revolution. And the materalism here is the materialism of fundamental physics. From what I can gather that materialism is the articulation of human beings and nature as machines and so its metaphysics is an expression of the technological mode of being.

Some solutions are better than none. What Heidegger does is find alternative practices that lead to, or imply a new mode of being, thst is alternative to the technological mode of being presupposed in the corporate solution to repairing the ecological damage.