I have to disagree when healthy Sam has only shown he is a 7-9 QB not damn good. I also think that if we look at last year before he was injured he was 3-4 he had one win against a winning team, Clemmons came in and had two wins against teams that went two games deep into the playoffs. An Clemmons did so with the same team Sam had played with. So does he have skills, for sure he does, but what makes a QB damn good is his ability to take his skills and turn them into wins and so far he has not done as such.
Your point is technically correct I suppose but there are also several aspects. Our D couldn't stop anyone early in the season, and they were experimenting with the spread and had no running game. We averaged under 50 yards rushing per game over the first four games while allowing the opposing teams to average over 126 and 30 points. In the games against Dallas and SF, we allowed 11 sacks with no running game while allowing them 200 yards rushing per game. You could be John Elway and Peyton Manning's love child and you are not going to win many games in the NFL with that kind of production and defense.
Meanwhile, during Clemens' games we averaged 140 yards rushing (take out the throw in the towel game at the end and it is 155+) even though everyone knew they weren't going to get burned by KC's arm. Was that the QB? Not hardly. In those games, we dropped our rushing yards allowed by 35% as well - down to less than 85 yards per game.
My point isn't to defend anyone. But to take what happened in those games and say it was because that is just what kind of QB we have is ignorant at best.
As to your other point about our O-line - you are also ignoring the fact that our offense was largely designed around getting rid of the ball fast to avoid the sack. That won't show up in the stats you chose.
I won't defend Sam against real facts and points where he is lacking but I will when it aims at forming a false image of our QB in the quest for change. Change for the better? Cool. Change because the team as a whole played like crap? Not so much.