You make fair points but the difference between college and the NFL is a gaping chasm, as I alluded to before there are exceptional college QBs who just aren't 3rd string NFL caliber. Exceptional college production does not mean the player will be exceptional in the NFL. How much of that 70 odd % of Manziel came from completions outside the pocket? How much of that 55% were wild tosses for Mike Evans to drag down? These are things NFL scouting departments will be looking closely at and as has been reported in the media many of them do not have a first round grade on Johnny Football.
Bridgewater is a very solid prospect, but you can't teach size (and remember, people like Rusell Wilson and Drew Brees are exceptions that prove the rule - size matters at the QB position) - which Bortles has - Bridgewater needed to tick every box in the run up to the draft to solidify himself as a top 10 pick, but has fallen at a few hurdles so don't be surprised if he falls on draft day in what many are calling one of the deepest drafts in history.
College completion rates just don't mean anything at the next level, because at the next level you aren't playing against college level talent - that's the reason why players who have been some of the best players in college history, like Tim Tebow, are now out of the game, and the reason why most scouts project a Bortles or a Carr as much better prospects for the NFL - the qualities they have simply project to greater NFL success compared to a Manziel, awesome as he was in his college career.
