The writer is from Australia so it's clear that he's biased toward Laver. Few years ago Peter Bodo admitted that he was biased toward Sampras when comparing as to who's the greatest. These writers are biased toward their countryman. If you want a writer to provide objective assessment between Federer and Laver, Steve Flink is a good example.
Federer > Davydenko > Nadal > Federer