What inhibits these guys from asking the searching questions?
Refer to Mr Trojan '81's response and there you have your answer.
Another reason is advertising revenue. Imagine you worked for a major Australian newspaper and had some bullet proof story about a hypothetical CEO taking bribes to buy a hypothetical airliner. Now imagined you published that story and exposed the board and management etc etc
Do you think that the hypothetical airline would be paying big dollars to advertise with your paper? Do you think your editor will be getting a business class upgrade next time?? Of course not......so they allow puff pieces here and there but nothing of any substance gets printed.
Personally I am very worried at the state of journalism in this country and the financial pressures that are being brought onto newspapers due to lack of revenue. We are heading into very dangerous waters without even realising it.