I think the rules have made the shut-down corner a thing of the past. Not only that, but WRs these days are just so physically superior to their CB counterparts. I can't remember of the last time I've seen a CB really have a standout performance.
That's because like say a left tackle, in most cases, if you don't hear a cornerbacks name called much during a game, it's because he's shutting down who he's covering and the ball isn't being thrown his way. The casual fan won't notice the fabulous game a corner is having because that players name isn't being called, but the coaches and GM surely will notice.
This is an extreme example because Deion Sanders was one of the best cover corners to ever play the game, but in his prime, multiple games could go by without his name being called much unless he got an INT because QB's rarely threw the ball to the guy he was covering. In his dominant days with Dallas, he only averaged 3 interceptions a year.
When teams have a good corner and he's playing well a whole half or game can go by and you rarely will hear his name called by announcers and that's not because he's playing poor, it's usually because his man isn't getting open and thus isn't getting passes thrown his way. More times than not, if a corner is getting lots of air time, it's because whoever he's covering is open enough that the QB is throwing the ball that way.
On the other hand, I've seen some absolutely dominant performances by LBs and safeties in which they essentially took over the game
The above is my point. You hear a safety or LB's name called a lot during a game because the position they play lends more to to it, but if a starting corner on their team has say only allowed one or two catches for 15-25 yards to a good receiver, you don't include him in having a dominant performance because that corner was barely mentioned. Plus, on top of that, average fans don't notice when a good corner is trusted enough by their coaches to play lots of single coverage and thus allows for a safety to cheat more on the run or slide his coverage elsewhere. Good corner play can allow that extra second or half second for the pass rush to get to the QB, but the fans watching on TV will have never seen that aspect of the sack because the camera was on both lines and the quarterback.
The coaches notice this stuff though, both the defense and offensive coaches and is why corners generally get drafted higher and get paid more than safeties or linebackers.
EDIT-- I am with you somewhat DB on safeties and it does seem NFL teams are placing a higher value on them the last 5 years or so compared to the past. With so much passing, teams need at least one safety who can play the pass well along with support the run.
