When Drew Brees threw for his 5,085th yard in Week 16, people everywhere went crazy. While their reaction to a record being broken that has stood since 1984 is understood, it really shouldn't be that surprising.
You see, the position of quarterback in the NFL is evolving. With defensive players becoming stronger, faster and more athletic, quarterbacks have been forced to improve and evolve.
Just look at the chart below to see my point:
Year Top Passer Yards 4,000-Yard Passers
As you can see from the information above, where 4,000 passing yards used to be a rare feat before 2005, it has now basically become the norm.
In fact, from 1990 to 2005, there were only 40 4,000-yard passing seasons. When you compare that to 2006-11, there were 43 4,000-yard passing seasons, with four 5,000-yard passing seasons.
That isn't to say that throwing for 4,000 yards in a season isn't impressive, it just isn't as impressive. Before 2006, Dan Marino's 5,084-yards seemed untouchable. However, with the league becoming more of a passer-friendly league, it became more and more apparent that Marino's record would finally be broken.
With the evolution of the quarterback, no NFL record is safe, and we shouldn't be surprised when they start falling more frequently.