I'll preface this by saying that, yeah, lots of NFL quarterbacks are having great, huge statistical seasons.
That's the way the league is now; it's to the point that a team without a 3,000-yard passer is in the minority and, usually, irrelevant come playoff time.
That said, there's a number of quarterbacks this year, guys with proven track records, guys who seemed as sure a thing as any to keep playing at a high level, who are seriously struggling. If nothing else, it's distressing to fantasy football players.
Look no further than the Ravens' Joe Flacco, whose team is 1-5.