I'm not a big fan of Sanchez, but to ignore Sanchez while building up Stafford and Bradford is ridiculous. Sanchez was a #5 overall pick, so I think the Jets thought of him as an end-all, be-all QB. I don't think teams use #5 overall picks on backup QBs.
Bradford has started better than most people expected, but come on. He averages 6 yards per attempt, which is awful, he's thrown as many INTs as TDs, which is expected, he's completing less than 60% of his passes, which is expected, and his rating is 72.3, which is awful and expected. Stafford has played part of 1 game this year.
Meanwhile, Sanchez is 4th in the NFL with a 105 QB rating and has thrown 8 TDs versus 0 INTs.