Here are the main arguments used to avoid addressing this fundamental question, employed by trolls, the government, and certain media wings. They often overlap, and usually it's a combination of all of them. Know that when you're talking to someone employing these arguments you're not dealing with an intellectually honest opponent.
The end result, however, has been to merely postpone the scrutiny not diminish it. And Muscat is aware of this too. That's why he's panicking. That's why, as Murdock points out "this Prime Minister has begun to resemble a frightened man whose public bark is hiding an increasingly toothless bite".