I remember talking to somebody once who said that they played Rock Band like they’d play any other video game, trying to beat it at the highest difficulty levels, without caring about which song was being played or how much they felt like a rock star or whatever while playing it. This was inconceivable to me, but maybe it makes sense to true gamers, who probably made up a fairly big part of the Rock Band core audience.
It's probable that GDB had IRL conversations like this, but I like to imagine he was thinking back to Damo talking about playing the game on mute early in the morning purely for its timing elements.