I suspect until just recently it was because of the negative gearing policies, but now that Labor has officially scrapped any changes I feel like the differences between the parties gets thinner and thinner.

3 things. 1. People always look after their back pocket. Any policy that reduce income or wealth is a vote loser 2. Rupert Murdoch owns a majority of print and TV media and has extreme bias for the conservative govt. People do not see any other viewpoints. 3. Extreme divide between rural and urban population. It is impossible to satisfy both. A pro-climate change policy in urban Sydney is a vote killer in regional Queensland.