This is the main reason why I like it. The current two parties have a choke hold on the government and a third (or fourth) party has no chance today.
Multi-member electorates are far more likely to produce multi-party systems. Australia's lower house is single-member electorates and remains dominated by major parties. Its upper house is composed of multi-member electorates (one for each state) and consequently, that's where minor parties and independents most frequently show up.