All that stuff about the NFL being a passing league with rules promoting scoring do not apply to this conversation.
From Elias Sports Bureau: The Pittsburgh Steelers' 24-0 defeat of the Seattle Seahawks marked two consecutive shutouts in the series, both by Pittsburgh. The Steelers beat the Seahawks, 21-0, during the 2007 season. No team had shut out another team in consecutive meetings since Atlanta beat Carolina twice in 2002.
The scheduling rotation should keep these teams apart for the next few seasons.
Most recent shutouts suffered by each NFC West team:
Arizona Cardinals: 38-0 at Seattle, Week 2, 2003.
San Francisco 49ers: 21-0 vs. Tampa Bay, Week 11, 2010.
St. Louis Rams: 35-0 at San Francisco, Week 4, 2009.
Seahawks: 24-0 at Pittsburgh, Week 2, 2011.
Also shut out Sunday: return specialists. They scored no touchdowns in Week 2 after collecting eight in opening week.