Federer's peer group were Safin, Ferrero, Roddick, Nalbandian, Hewitt. Four of those five were former world number ones. Not to mention, the remnants of the previous generation who were no chopped liver either, and still playing good tennis - the likes of Kuerten, Moya, Agassi... again, all former world number ones and playing well enough to be relevant.
Throw other guys into the mix like Haas, Davydenko, etc. and combine that with the fact that over thirty "Over 30s" made the main draw at Roland Garros this year brings me to the conclusion it was far from a weak era.
I'm always kind of tickled when people say Federer had it so easy. As Murat explained - he turned around all the Head to Head's against his peer group from a lopsided losing margin in some cases (Hewitt, Nalbandian). He made it look easy because he raised the bar to a level that took him beyond the rest of the tour. People sneering at the likes of Roddick and the Fed/Roddick H2H would do well to remember Roddick led his H2H with Djokovic 5-4. Even Davydenko has a H2H over Nadal.
In the climate of "What did you do for me yesterday" thinking, these players get lost in the mix. Hewitt isn't even a patch of the player over the last 5 years than he was from 2000-2005. Roddick was a far more dangerous propostion in the 2003 than he was in 2012. Anyone other than Cali used to watch a peak Nalbandian? Unfortunately, with a lot of "fanboy" thinking, people look at the declined versions of these players years later and assume that was what Federer had to overcome at the time. It wasn't.
He then had the young blood coming through - the next generation on from his peer group - Nadal, Djokovic, Murray... All top players who rode the path Federer set in raising the bar. Who have the current generation got coming through? Dimitrov, Tomic?? Please... it's not even on the same page... Which is the weak era again?
Federer's best years were 2004, 2005 & 2006. Add in 2007 I guess, but the previous three were his absolute peak. As Djokovic will attest from 2011 - it's difficult to dominate for such a sustained period. Nobody else has dominated for a three or four year period since the turn of the century other than Federer.
I'm not really sure what the heck people expect from Federer now or what he needs to prove. He's 32 years old, 5 or 6 years past his true prime, has played more matches than anyone else on the tour.
He'll still be "relevant" until he hangs it up and might (I hope) have another spike upwards before he hangs it up... but he owes nothing to anyone. Enjoy the twilight of his career while you can. He's still the greatest player I've seen over the course of a career, bar none.