Fed didn't lose a single set at the Australian Open. Fed only loses in small tournaments on hard courts.
Fed has lost multiple times on hard courts every single season like I said. Let me show you:
2004 Fed losses on hard courts
Rotterdam quarters-Henman defeats Federer 3-6 6-7(11)
Cincinnati 1st round-Hrbaty defeats Federer 6-1 6-7(7) 4-6
Olympics 2nd round-Berdych defeats Federer 6-4 5-7 5-7
2005 Fed losses on hard courts
Australian Open semis-Safin defeats Federer 7-5 4-6 7-5 6-7(6) 7-9
Year end Masters finals-Nalbandian defeats Federer 7-6(4) 7-6(11) 2-6 1-6 6-7(3)
2006 Fed losses on hard courts
Dubai finals-Nadal defeats Federer 6-2 4-6 4-6
Cincinnati 2nd round-Murray defeats Federer 5-7 4-6
2007 Fed losses on hard courts
Pacific Life 2nd round-Canas defeats Federer 5-7 2-6
Nasdaq round of 16-Canas defeats Federer 6-7(2) 6-2 6-7(5)
Fed losses in Masters events are in significant hard court events too, not just "smaller" tournaments. If you consider a Masters events a "small tournament" then the tournaments that are not small are just the Grand Slams and the year end Masters. That would mean the clay court season is basically just 1 event, the summer hard court season just 1 event, which would be a silly way to look at it. Even at that Federer loses in those events sometimes too on hard courts, as his 2005 Australian Open semis and 2005 year end Masters finals show.
You say Federer did not lose a single set at the Australian Open. That is not at all indicative of what he usually faces in a slam final on hard courts. In the 3 slam finals he played on hard courts before that he looked halfway through the match as if he would probably lose in fact. The 2006 U.S Open final with Roddick he was 1 set all, and looked about to go down a break. The 2006 Australian Open final he looked like he was about to go down 2 sets to 0 to Baghdatis.
Then even vs an old Agassi in the 2005 U.S Open final he was 1 set all, down a break at 4-2 in the second. You certainly never had even slight doubts Nadal would win any of his French Open finals halfway through the match.
Fed's dominance on hard courts does not even approach the monopolizing and tedious dominance Nadal has had on clay which ruins any competitive value or interest in the clay court season and makes it all but unwatchable. There is a reason 2 Masters events are being demoted to lesser status next year.