There's also the receivers who run the wrong route that lead to interceptions, and the passes that are tipped up in the air that lead to interceptions, and of course just the good defensive play of opposing CBs that lead to interceptions...none of which has anything to do with Campbell misreading defenses.
Btw, Campbell was 19th in the league in terms of INTs thrown, behind the likes of Eli Manning, Jon Kitna, Carson Palmer, Derek Anderson, Tony Romo, Drew Brees, Marc Bulger, Brett Favre, Phillip Rivers, Peyton Manning and Matt Hasselbeck.
Of course he played in less games, so it would be more accurate to show an INT/Attempts ratio:
Young: 1 INT every 22 pass attempts
Bulger: 1 every 25 atts.
Eli Manning: 1 every 26 atts.
Romo: 1 every 27 atts.
Warner: 1 every 27 atts.
Kitna: 1 every 28 atts.
Anderson: 1 every 28 atts.
Palmer: 1 every 29 atts.
Rivers: 1 every 31 atts.
Cutler: 1 every 33 atts.
Brees: 1 every 36 atts.
Favre: 1 every 36 atts.
Peyton Manning: 1 every 37 atts.
Roethlisberger: 1 every 37 atts.
Campbell: 1 every 38 atts.
Hasselbeck: 1 every 47 atts.
So since you believe that INTs are only the result of the QB's inability to read defenses, your logic dictates that Jason Campbell can read defenses as well as Drew Brees, Brett Favre, Peyton Manning and Ben Roethlisberger.
And just to cut you off at the pass, you were criticizing the number of INTs that JC has thrown, NOT the number of TDs thrown or the number of games won. So don't embarrass yourself by saying "But at least those other QBs throw a lot of TDS!" or "At least those other QBs win games!"...