I feel a little sad Steffie,
It is easy to evoke emotions and direct blame. No doubt your targets have a hand in our current dilemma.
Mr Abbott and Turnbull aren't the cause of our problems, nor the Aussie public at large who no doubt would say in mass they do think about their political choices. I'd suggest the cause of our problem is more fundamental. The NBN is just another symptom of the problem.
We may be a democracy in that we can all vote (age permitting) and hold differing views or positions. We are less of a democracy in that many of the decisions made on our behalf by our governments are not universally popular. Some decisions according to opinion polls often have the support of many fewer than half of us.
We can't change our past and history. There is no point in complaining about it. Perhaps we all need more understanding of it.
One take on our poitical system - It is what it is because it made sense to those empowered by late nineteenth century British Politics. Even the so called father of federation Sir Herny Parkes as the Colonial Secretary to NSW was in part doing the bidding of the then government of GB in encouraging a more independent future for the colonies. He was instructed to pursue Federation. It was a future where the Australian Colonies would stop calling on GB for financial support but also one where we toed the line for GB and retained business connections to its favour. It was not then a universal desire of all in the Australian Colonies to go free lance! And it was also subject to the sanction of the then parliament of GB that we should do everything to fit into its vision.
We subsequently inherited a system that while far reaching in formulation as a "Commonwealth" adopted much that was not so good. This included the basis for the "White Australia Policy" and the disempowerment of anyone not of European descent.
Our current electoral system was deliberately designed to return only first and second place to represent us. We don't have any true form of proportional representation. It is the two parties in our two party preferred system who hold all the cards if this is to ever change? The LNP response to the recent recommendations for more inclusive recognition of the earlier Australians suggests any change at all to our political values or system that affects the status quo will be summarily dismissed. Unless some may argue we can limit it to only two parties and remove all minor parties from the senate.
Both major parties differentiate on major issues whether by solution ( the better NBN solution) or need (Not for Profit Industry Super funds vs Only for Profit Super Funds). This often leaves no room for consensus. They can also exclude solutions due to the extreme opposites of position each adopts.
There is enough evidence through the consumer actions of Choice members of how difficult it is to change our lot for aspects of our lives as consumers that typically don't even rate on the agenda at election time. Both the major parties it could be argued avoid consensus and choose to deflect/ignore non core issues.
Unfortunately in the 2016 election typically 1 in 4 Australians didn't vote for either major party in the House of Reps. Only 2 in 5 really wanted a Liberal/National Government. Slightly less desired the ALP. As you noted our current NBN solution has been determined to the benefit of those most likely to vote for the LNP.
Ultimately the NBN will get a score. If you live in a marginal electorate you may do better.
Ultimately the NBN will be sold off. There will be winners and loosers.
Rather than fix the NBN my guess is our political system will reject more public investment. If you want good NBN then Aussies will simply sell up and move! How do I know this to be reliable! One of my local real estate professionals told me that having good NBN or no NBN will not affect property prices! And we all know how reliable real estate sales staff are?
On average 4 out of 10 Australians will agree the NBN we have is better than the one we didn't get. Not enough (9 out of ten experts) to sell toothpaste or hair product - but just enough to get re-elected?
I'd hope that nine out of ten Choice members agreeing still has the power to influence some of the NBN outcomes.