Those are some creative stats you've worked up there. I don't think I've ever seen somebody try to argue that a QB is successful based on the number of games with more TDs than INTs in the individual game! (Are you arguing that it's better for your INTs to be distributed 3,0,0,3,0,0 instead of 1,1,1,1,1,1?)
Regardless, I think you were misinterpreting my intent. I wasn't trying to defend Sanchez so much as offer an "he is what he is." He's very young (24), inexperienced, and inconsistent. The fact that he's a 3rd-year starter who lead his team to playoff wins the past 2 years quite naturally leads everyone to underestimate that.
You mention how Fitzpatrick has started relatively few games despite being in his 7th season. Absolutely -- that's because he didn't play terribly well when given starting opportunities. If you're a 7th-round pick, that's what happens: you play badly, you sit and LEARN, as you should. But when you're a high first-round pick, dubbed the Sanchize by your coach before you've done squat, you just keep starting regardless.
I can't help but wonder what kind of QB Sanchez would be if he'd spent at least a season apprenticing to a solid veteran.