Does seem the entrenched powers want to undermine the Greens as much as possible.

I hope there's a lot of Greens volunteers in Prahran talking to people.

Scratch a liberal: a fascist bleeds.

I don't think it is "unforgivable". I reckon it might be unforgivable if Labor had preferred One Nation over the Greens; but to just not give any preference at all is... not really that bad in my opinion.

On the one hand, I think voters should never use how-to-vote cards at all. Voters should build their own understanding of which parties align with their values, and vote accordingly. And so Labor not suggesting any preferences seem fair enough to me.

But on the other hand, a party's listed preference is a strong indicator of how that party sees itself in the political landscape. Its an indicate of how their values align with the values of others, and hence an indicate of the parties values and priorities. So although I don't think voters should follow the how-to-vote cards, they can be useful sources of information. And in that sense, Labor saying "we have no preference regarding the other parties" is effectively a way of saying they agree with One Nation just as much as they agree with the Greens. And that could be seen as unforgivable if interpreted in that way.

Stop voting single issue

accept that election day is the start point of developing and expanding policy, not the end point

but who are we kidding, people will vote to maintain high house prices/negative gearing and against the COL increases

I never take how to vote cards. I go in with my own prepared list. Sometimes finding meaningful statements from some candidates isn't easy, sometimes they are well meaning, but looneytunes. It's usually easy to get first and last, the tricky bit is sorting out the middle.