I don't entirely disagree here, but I think you've mistaken the conversation a bit. Transplant was talking about how you'd rank the QB's 2015 season specifically.
In 2015, Luck played in 7 games and didn't look good; Ben played in 12 games, had a worse TD% and nearly triple the TO%; Carr had decent overall numbers on high volume, his YPA and Turnovers suffered because of it; Smith had fewer YPG, worse YPA, and scored fewer TDs and 1 more INT than Tyrod in 2 additional games; Ryan had 3 fewer TDs and 15 more TOs in 16 games, and a very similar YPA to Tyrod.
That's not to say Tyrod is a better QB right now than any of them (though I think he's better than Smith), but based on that year alone he produced better than some IMO.