The lack of opposition is a consequence of the concentration of traditional media in Australia. News Corp owns 70% of the print media and they will never strongly criticise the (right wing) Liberal party as long as that party does what Rupert Murdoch tells them to do. They will, however, relentlessly bash the Labor party, so that party has been playing the "small target" and never doing anything that would allow News Corp to criticise them.

A lot of the other media is owned by Fairfax-Nine, which again has ties to the Liberal party (e.g. Peter Costello) and similar remarks apply.