Here is my take:
Under Fitzgerald over the last few seasons, NW has traditionally had a hard time coming out of the gate when combined with even a marginal amount of expectations or sustaining that success within a season.
2017:
Beat an eventual 3-9 Nevada team 31-20 at home
Beaten by Duke 41-17
2016:
Beaten by a good MAC Chamption WMU 21-20 but followed up by a loss to 1AA Illinois State 9-7 to start 0-2
2015:
Started the season off well against Stanford and continued through the season to a 10-3 record.
2014:
Started the season beaten by an eventual 5-7 Call team and a NIU at home to start off 0-2. Finished 5-7.
2013:
Started off 4-0 and looked to be a favorite in their division but once expectations were raised, NU went 1-7 in their final 8 games beating Illinois 37-34.
2012:
Started off 5-0 with victories over Syracuse, Vandy, and Boston College. IMO, this was NU's best team since the Darnell Autry years. Ended up 10-3.
2011:
Beat an eventual 4-8 BC team 24-17 and then lost games 3-7 to end the season 6-7.
2010:
Started off 5-0 before losing to Purdue, MSU, PSU, Illinois, Wisconsin, and Texas Tech to finish 6-7.
2009:
Beat Towson before struggling with EMU and losing to Syracuse and Minnesota to start 1-3. Also struggled with Miami (OH) in game 6.
2008:
Ended the season 9-4 after starting off 5-0.
My point is that NU has a bit of history dropping games early in the season or later in the season when the expectations get picked up a bit. It feels to me that a lot of NU fans have some high expectations given the 10 win season last year but history seems to show that NU has a difficult time sustaining success either from season to season or within a season itself.