Every sack is different. Most sacks that Rodgers takes are his fault. The sacks that David Carr takes he is just fucked on most of the time. Big Ben is a nice mix. Cam, most of them are his fault, etc...
But, Rodgers has stated time and time and time again that he would rather take the sack than risk a pick/fumble trying to get the ball away under duress. I think it's a sound strategy as long as you have faith in your offense to move the football.
I think this plays into that laziness you were talking about earlier. If someone wanted to chart sacks, and who's fault it was, I don't think it'd be that difficult.
1. Lineman blew protection/beaten off ball - Not qb's fault
2. Failed to recognize blitz/adjust protection/routes - Qb's fault
3. Held onto the ball - Qb's fault
4. Indeterminate - 0.5 faults
Then you'd have to take the game situation into account, of course.
In the end, a lot of stats are worthless, especially if you can torture them to admit to whatever you want.