Cornerbacks in today's pass happy NFL are among the most important positions to fill with guys who can shadow the games best wide outs. Even with the best of pass rushers teams can fall apart on the back end which can lead to disasters.
Recently more money has been pumped into the position than ever before with teams attempting to sign, trade for, and draft the next Champ Bailey, Darrelle Revis, or Antoine Winfield.
Just look at the impact that Richard Sherman, Charles Tillman, Casey Hayward, Robert McClain, Tim Jennings, and Patrick Peterson had this year for their respective defensive units. They were vital to anything the defense did.
Every season there is a batch of guys who are burned, beaten, or fried (whichever verb you wish to describe a terrible play for a corner).
For some teams the one on one battles that these guys lose on an every game basis can make or break a team's season. Just ask Washington, Dallas, Philadelphia, San Diego, Jacksonville, or Detroit. They all hope they can pick up the broken pieces from last season.