Yes its 20 to 12 so far but Feds run started in a pretty weak era, who were his main threats Hewitt? Safin? Roddick?
Jokers 12 have come against much better opposition.
This is a complete fallacy. Look at the form of the competition Fed went through when he absolutely dominated the tour for four straight years (04-07). The Gonzo's, Roddick's, Nalbandian's, Hewitt's etc easily collect plenty of slams if it weren't for Fed. And in those years the Nadal's and Djokovic's were frequently sent packing by these guys (AO 2007 is one good example, where Nadal was obliterated by Gonzo).
And fwiw, Safin is one of the most naturally gifted tennis players of all time. Watch the 2005 AO Semi Final when he beat peak Federer. I don't believe I've seen a higher quality match in the modern era (save for perhaps Wimbledon 07/08 finals).