That's quite different than the idea that 2010, when Humble Bundle launched, was 'long before indie games were a valid genre'. Braid was a giant hit on XBLA in 2008, the very existence of a platform like XBLA from a major publisher suggests Humble Bundle didn't have much to do with creating or validating this market. It's certainly become a substantial player in it.
Braid was never marketed as an "indie game". Outside of tigsource and the IGF, "indie games" as a category didn't really take until a few years later (with things like Super Meat Boy and it's inclusion in 'Indie Game : The Movie'). The term was largely unknown until 2010 or so
That graph doesn't show what you think it shows. Google has a topic for this (which would be odd, if it was unknown in 2010) and if the trend graph measured how well something is known (which it doesn't) then 'Indy Game' as a topic was about as 'unknown' in the US this July as it was in February 2008. Which is obviously silly.
Braid was one of the three games included in "Indie Game: The Movie." What exactly would Jonathan Blow have needed to do to "market it as an indie", giant glowing arrows on the title screen saying "this is an indie"?
Humble Bundle would not have made any sense nor would have had much to sell if indie games weren't a 'valid genre' in 2010.