You can:
1) Blame the Tigers for not showing up to play ball.
2) Blame the Giants for playing great ball.
3) Blame the mainstream media for not hyping up the series as if it was a Yankees/Phillies World Series
4) Blame FOX (mostly Tim McCarver) for their boring coverage (except for their ultra slow mo 20,000 fps camera!)
(I'm generalizing here) What many people do not understand/appreciate, is what the Giants did to get to the World Series. Having to win 3 straight games in both the NLDS and NLCS. Bitter Reds and Cardinals fans probably didn't want anything to do with the World Series knowing their team was 1 victory away from moving on.