You forgot 2011
2012- Nadal played one of the greatest matches ever, a match that Djokovic *won*, unlike Federer's long list of failed comebacks/wins in great matches against his competition. Of course Rafa at RG. Rafa was the same non-factor at Wimbledon as he was at RG the only time Roger won it, and unlike Roger, Novak didn't get the trophy so his resume wasn't inflated. USO he lost to Murray, so again no inflation.
2013 - So now Nadal being absent the AO is a mark against Novak, when his presence in one of the greatest matches ever doesn't count for him? Of course Murray played great that year who is better competition than Roddick and Philippousis.
2014- Federer played excellent tennis at Wimbledon and simply lost to the better player who won a tight match. Even if we accept the line that Federer was "post-prime" (which contradicts him btw) he was still much tougher competition than Roddick, baby Nadal, ancient Agassi, Baghdatis and so on
2015 - See above (Federer was so good this year he won 44 consecutive sets against non-Djokovic players, and also said he was a better player than ever before)
2016 - Federer was brilliant at AO, and Novak just got the better of him (again).
All in all, his competition was clearly better than a who's who of Roddick, Philippousis, Baghdatis, ancient Agassi, Kiefer, baby Nadal, Hewitt, Safin, and baby Novak (if you want to even count him).