Are you trying to compare the Patriots defense with the Steelers' defense of last year? The defense that only gave up 14 ppg? Sanchez's 102.2 rating in that game was the 3rd best game a QB played against the Steelers last year. Brady had the best at 117.4 and Rodgers the 2nd best at 111.5.
The year before, Sanchez was a rookie QB playing on the road in the AFC Championship Game. He was a rookie that had only started for one year in college, yet was now playing in the 2nd biggest NFL game of the year. Henne has never, not even once, experienced that kind of pressure.
You've made the absurd implication that the first game of the season and the conference championship game are comparable. If Chad Henne had put up those numbers in a playoff game, or even a late regular season "win and you're in" game, I'd give him more credit.