Actually when he throws 1-10 yards he completes 77.1% of his passes, from 11-20 he completes 66.7%.
JP is 47.5% from 1-10 and 54.3 from 11-20.
Peyton Manning is 67.1 from 1-10 and 68.3.
With that said, if he wants to remain the starter he needs to go deep a lot more often and stop playing it so safe. If that is coaching or the QB I don't know.